Hi,
My friends stock 93 Jap RX7 developed an ECU fault and lumpy idle, we retrieved the code from the ECU which was 45, Charge control solenoid, so we took the rats nest to bits tested all the solenoids and 1 way valves and replaced all the hoses and tied them up and put it back together with exactly the same fault, we even changed the solenoids around just incase.
We cant seem to clear the fault and fix the dodgy idle, is there anything else we should try.
Can anyone also confirm the correct way to test the turbo control solenoid, the one with the Mitsubishi logo cap on it, is that cap actually meant to be air tight becuase it leaks air our slowly. If someone can confirm I will retest this because I am unsure about how it should function.
Thanks,
James
Some more info:
http://www.fd3s.net/boost_problems.html (http://www.fd3s.net/boost_problems.html)
6. Charge Control Actuator:
When closed, this prevents Primary boost from going into the Secondary Turbocharger. This valve seals the air passage the same way as the throttle butterfly valves. This remains closed until 4,500 RPM AND Secondary boost pressure is the same or more than Primary boost pressure.
I beleive this is sticking open at "idle" which is around 2,500rpm on the car at the moment, this is blowing air out of the secondary inlet.
Previous post is wrong, I think the actuator is correct, it is closed at idle and that is what must be pushing the air out of the inlet ?
Still stumped as to what is causing this fault code!
Hi
Did the car idle high before you replaced the tubes? It sounds like you have an air leak, aside from a solenoid problem.
To test the solenoid, pull the electrical connector off, get two bits of wire long enough to reach from the battery to the solenoid, and touch one of them to either contact on the solenoid. you should hear a definate CLICK sound if it\'s working. Test one of the others this way for a reference to work from.
If it does click, then there\'s probably a fault with the wiring, and you\'ll need to check continuity between the sol\' connector and ECU.
If it doesn\'t, you\'ll need a new solenoid. I can probably find a spare one if you do need it.
Regarding the high lumpy idle, try this:
http://www.mazdarotaryclub.com/forums/showthread.php?t=40062
Also check for hissing noises while running, which would indicate and air leak. A neat trick is to use a piece of hose, with one end put to your ear, and point the other end in and around the inlet manifold. You\'ll soon find where the hissing noise is coming from if you have one.
HTH. Good luck.
Ian
Hi, Cheers for the reply
Yea, Air leaks could be attributing the bad idle, which is something I wil triple check again, been through it plenty of times and pretty sure we dont have any leaks after the throttle body, im more concerned about the dodgy solenoid valve, its almost definitly a wiring problem because the solenoids work.
Gone through the Vac diagram numerous amounts of times and everything looks ok there, everything is tied on, replaced the gaskets between throttle body, and ACV, so i think wiring!
Im just tracing my way through the wiring diagrams and will follow the appropriate tests for finding the short circuit.
Cheers
James
More info on the problem:
I took the manifold back of and tested the solenoids and wiring
1) Test solenoid connector to ensure continuity to battery and ecu, this was fine
2) Test to ensure solenoid was not active when the car ignition was on (car was not started) this was fine
3) Performed the same tests with the charge releif solenoid just for reference and it was the same.
4) Managed to clear to fault code
Reassembled and started the car and checked the fault codes at various stages to ensure it did not return and it didnt until we started the car.
Would the fault not have returned until I turned the car on without the jumping the terminals?
Im a bit stuck now, maybe im going off in completly the wrong direction! lol!
Thanks,
James
Sorry dude, I forgot to reply yesterday.
What\'s the latest?
Well, i looks like it must be a short between the battery and solenoid, havent had time to confirm this yet but will be at the weekend.
Im wondering if the circuit is going to ground to early? I cant see it being anything else (maybe a knackered ECU not activating the solenoid). Im going to try the factory manual procedure for finding the short, eg disconnecting everything and checking continuity whilst replacing each component, then I guess inspect the wiring at that point.
Good post about sorting out the idle, this is going to be a great help once I clear the fault code :)
Thanks Again,
James
:D Good luck!
Just a few more suggestions for finding the fault...
Disconnect the plugs from the back of the ECU. (Page z-32 of the 94 FSM)
Find the pin on the plug that goes to the solenoid you\'re having trouble with.
Labeled 4R. (Should be fourth from the left, on the bottom row of the largest connector if you have the clip facing up.)
Test it for resistance between the ECU plug and solenoid plug.
Then test for shorts to ground and 12V.
You\'re right, the ECU does ground one side of the relay. The other side is connected to a 12V line switched by the EGI main relay through the 30A EGI fuse.
Test to see if it\'s getting 12V when the ignition is turned on.
I tried the continuity tests and there was continuity from the ecu side of the connector to the ECU connector, so no short on that side
Also, cant remember what I tested for the batter side, but I think there was continuity from the battery side of the connector to a GND terminal in the Diagnosis terminal, but that could still indicate a short?
I should probably be checking for continuity between the battery side connector AND positive battery terminal with the ignition on?
Thanks,
James
Hmmmm. Dont think it sounds right that there would be continuity from battery side to GND. This could be your problem. There ought to be between 12V and battery side of sol connector when the ignition is on, but not off. try putting the tester between +12V and the battery side of the connector, and getting someone to turn the ignition on and off. You should find that it makes a circuit when ignitoin is turned on, and not when it\'s off.
Ok, im have been messing around today and I am trying to isolate the 30amp EGI circuit so I can test for shorts (using the factory manual procedure)
Can someone confirm the correct way to do this.
So far I Have:
Disconnected:
30Amp egi fuse
EGI Main Relay
Injectors
Air Pump Relay
ECU
Turbo Control Solenoid 1/2
Im having trouble locating the X-05 Common connector for the Emissions Harness to Front Harness and the Diagnosis Module, these appear to be the only things left on the circuit according to the wiring diagram at http://www.wankel.net/~krwright/files/manuals/1993%20RX-7%20FSM/_Z_Wiring_Diagram.pdf (http://www.wankel.net/~krwright/files/manuals/1993%20RX-7%20FSM/_Z_Wiring_Diagram.pdf)
With the ignition on I get continuity over the 30Amp EGI Terminal, I just wondered if I need to test with the ignition on or off? I may have continuity because of the X-05 Connector and the Diagnosis module still being connected.
This is driving me NUTS! :) Am I trying to find this fault correctly, or am I way way off!
May also need to disconnect X-07 (Front/Dash harness connector) also. This seems to be in the circuit.
Thanks,
James
Sounds like you\'re having fun. I spent ages trying to find the X-05 connector myself. Don\'t forget that all the manuals are yank, so some stuff isn\'t labeled as being in the right place for our left-hand drive cars. The diagrams appear to be correct, but the component locations seem to differ in places.
The X-05, If I recall correctly, is the blue connector, down in the passenger footwell that connects the engine loom to the car loom. You\'ll have to get in nearly upside down to try and get to it, as it\'s tucked up behind all the trim near where the engine loom goes through the firewall.
with the ingnition on, you should get continuity over the EGi fuse, as the EGO relay will activate the circuit.
I think the X-07 circuit is a big blue connector underneath the stearing column, but I could be wrong about that.
Anyway, you seem to be headed in the right direction.
Fun? lol
I think im missing some fundamental understanding of all of this.
The short says disconnect all the connectors in the circuit and then reattach until there is voltage going over the 30amp EGI Fuse.
So i have removed everything, injectors, solenoids, X-05, X-07. If I Disconnect the EGI Relay I dont have any voltage over the fuse, as expected. If I connect the relay and dont turn the ignition, theres no voltage as expected, If I turn the ignition on I get voltage over the EGI Fuse ?? thats not expected is it?? Surely for voltage to be present over those terminals the circuit must be grounded somewhere, and I cant see anywhere on the diagram to indicate this, so whats happened?
Does this mean that somewhere after the EGI Relay the circuit is shorting out?
Next question, is the only way to sort this I guess is to rip the wiring out from the fuse onwards and then inspect it all the wrap it back up again? Is there a method to isolate the fault even more? (if I was doing it right in the first place!)
Hmmm Sounds like a big task lol
Ta,
James
LOL. Arrrgghh, dude, you\'ve lost me there. I\'ll have a look in the manual and try to come up with a comprehensive list of things to check.
When I get a problem like this I always try to sit down with the manual and redraw the circuit myself with only the components I\'m interested in included. This will give you a clear view of what to expect, and helps just having the whole circuit on one page rather than two. Give it a go, and try to think about what voltages you\'d expect at various stages in the circuit, and in its various different states.
Try it and see what you come up with. I\'ll do the same.
Thanks man,
Just about to take the dashboard assembly out so I can get to all the wiring.
I *think* the problem is on the Black/White wire between the EGI Relay and the X-05 Connector. I cut this wire at the EGI Relay and the problem went away, which ruled out the problem existing between the EGI Relay and the injectors (the orange/black cable out of the junction box).
Since I have the X-05 connector disconnected the circuit must be being completed on the way.
Cheers,
James
I cut into the wire at the EGI Relay and ran a new wire from there to the terminal X-05 connector, basically spurred of for the X-05 bit and it seems to have done something, maybe! I used to get connectivity to the +12v and the Terminal on the solenoid with the Ignition off/on now I only get it when the ignition is on.
Some progress - it may not have fixed the fault but I reckon im getting closer.:)
Thanks,
James
Sounds like you\'re making some progress. I\'ve re-drawn the diagram with just the bits you\'re working on - I hope it makes it clearer to follow.
I\'d say you\'re on the right track. With the ignition off you should not get 12V with the ignition off. I\'m a bit miffed as to why you\'d get 12V with the ignition off! When I had my lighting problem, I eventually found that the pin in one half of the connector had burnt out, and wasn\'t making proper contact. It was a bitch to see and I only found it because things started working when I wiggled the connector around. I narrowed it down to that connector by exposing bits of the loom and digging one of the multimeter probes just through the insultation of the wire in question, and testing for resistance back to the start of the circuit. I gradually moved down the loom until I found roughly where the problem was. Had my head in the footwell for bloody ages, but was well worth it to find the fault! I couldn\'t believe how thin the wire was to carry the kind of current the fuse for that circuit is rated at. Still, that\'s car wiring for you.
Thanks for that, very very helpyful.
Strange how I think the fault is between the EGI Relay and the X-05 connector yet it would look like that would take out all of the circuit after that, which is every solenoid.
According to the FSM the Charge control solenoid is "ON" at startup does this mean it must have +12V at startup?
Im trying to get my head around the workings Charge Control Valve, Its got two points on it, it for receiving vacuum/pressure, one side attached to the primary turbo charger side of the Y-Pipe and one side connected to the Charge Control Solenoid. For this actuator to close (and close the butteryfly) does it need a pressure difference between the primary turbo charger side and the Solenoid side (i.e Solenoid should provide less pressure)
How does the solenoid being "ON" at startup provide this, routing the same part of the turbo system at both sides of the actuator?? In my backwards world it would need provide the secondary boost pressure at startup which will be less than primary whcih would close the butterfly valve, allow the secondary turbo to spool and then when the pressures matches the valve would open??
BUT in order for there to be a pressure difference to exist the valve must be shut in the first place!!! lol
My head hurts.
James
Ok, the solenoid must be ON and receive +12v because the vacuum is acheived by the vacuum chamber and the check valve.
Cool, getting a better understanding.
So, I have to get that solenoid to be active when the ignition on, which is the definitly the problem now!
Mate, I know, it\'s a total nightmare. Getting those little flashes of understanding is in my opinion a most valuable piece of learning. It\'s the things like that that you\'ll never forget. Glad you\'re making some progress. It does seem funny that it\'s only 1 solenoid affected. Have you found the part of the loom that the 12V B/W wire branches to the different wire\'s that feed all the other sols? I\'m not sure how it branches, as it\'s not very clear from the diagram.
You might have been over this already, but just to refresh my memory.
You something very near 0 resistance between 1 pin on the solenoid connector and the relevant pin on the ECU connector?
Get 0V between the 12V side of the sol connector and the batter -Ve terminal when the ignition is off?
Get 12V between the 12V side of the sol connector and the batter -Ve terminal when the ignition is on?
Do you get 12V with the ignition on to the other sols?
Another good step might be to remove the EGI relay and bridge the switched terminals. On the relay it\'ll have a similar diagram to how it\'s shown in the FSM, and will tell you which pins are connected to which bit. The pins will be labeled. ignore the coil ones, you dont want to short them. Give me a shout if you need a hand deciphering it. Then work out which sockets the pins fit into on the relay board, and put a wire between them. This should give you 12V to all the sols regardless of the ignition state, and takes the relay out of the equation.
HTH
I had another dig around last night, and I what I did was put the multimeter between the B/W cable in the X-05 connector and the Charge Control pin in the ECU, and then put a wire over the solenoid connector, this had continuity, so from the X-05 connector right the way to the ECU we have a circuit, but NO current throught solenoid with the igniton on which is wrong!
What im going to do is check each solenoid on the circuit diagram you kindly put together in the same way and ensure that the circuit is fine from that respect.
I also need to check the common ground for the solenoids, e.g X-05 terminal to the common solenoid ground bridging the terminals of the solenoids. Is it a good idea to do that, checking for resitance through the ECU? its not going to damage it is it?
Ill check each part of the circuit for resitance etc.. mark it on that diagram and post my results, it may appear what the issue is to someone who knows that they are doing :)
Thanks,
James
I had another dig around last night, and I what I did was put the multimeter between the B/W cable in the X-05 connector and the Charge Control pin in the ECU, and then put a wire over the solenoid connector, this had continuity, so from the X-05 connector right the way to the ECU we have a circuit, but NO current throught solenoid with the igniton on which is wrong!
What im going to do is check each solenoid on the circuit diagram you kindly put together in the same way and ensure that the circuit is fine from that respect.
I also need to check the common ground for the solenoids, e.g X-05 terminal to the common solenoid ground bridging the terminals of the solenoids. Is it a good idea to do that, checking for resitance through the ECU? its not going to damage it is it?
Ill check each part of the circuit for resitance etc.. mark it on that diagram and post my results, it may appear what the issue is to someone who knows that they are doing :)
Thanks,
James
Quote from: imebgoI also need to check the common ground for the solenoids, e.g X-05 terminal to the common solenoid ground bridging the terminals of the solenoids. Is it a good idea to do that, checking for resitance through the ECU? its not going to damage it is it?
Common ground? You\'re got me confused there. Remember that the ECU grounds each solenoid individually. They have a common 12V feed.
That\'s interesting about having a circuit. What resistance did you get?
What resistance do you get if you measure accross the solenoid pins with nothing connected?
I think I\'m getting a picture of what\'s going on. Would you humour me and measure voltage between the green and red points marked on the new diagram and post back your readings. Do each test with ignition on and off.
The values in green are expected values with ignition off Values in purple are expected values with ignition on.
At points 5 and 6 I\'m not sure what the state will be. This is dependant upon whether this is turned on, and turns off at a certain point, or starts off and turns on after a certain point. I can\'t remember!
Either way, don\'t be suprised if you see 12V at either of those points.
This will indicate that the ECU has turned off the solenoid, as it has let the side that it controls \'float\' up to 12V. This means there is no voltage accross the solenoid (both sides are at the same voltage at this stage), therefore no current will flow, and there is no energy to activate the coil inside.
If the ECU has turned the solenoid on, it will pull the leg of the solenoid that it is connected to down to ground. This means that 12V has to be dropped over the the coil, current flows, and it activates. Don\'t fall into the trap of thinking that seeing 12V on the ECU side of the solenoid means that it should be turned on - this is not the case.
OK, ill measure according to the grid.
One thing, just to clarify im using the multi tester correctly, how do I measure voltage at a single point, I haev a multitester with a +/- terminal do I just one terminal at the point in the diagram and the other on the battery negative?
EDIT
What I meant by the common ground was seeing if there was continuity to ground after the ECU, eg from Point 5 on the diagram to ground after the ECU ?
Thanks,
James
Quote from: imebgoOK, ill measure according to the grid.
One thing, just to clarify im using the multi tester correctly, how do I measure voltage at a single point, I haev a multitester with a +/- terminal do I just one terminal at the point in the diagram and the other on the battery negative?
Yes, that\'s it.
Quote from: imebgoEDIT
What I meant by the common ground was seeing if there was continuity to ground after the ECU, eg from Point 5 on the diagram to ground after the ECU ?
Thanks,
James
Ah, no worries. When the ECU is trying to activate the solenoid you should find very low resitance between the pin and battery -Ve terminal. When it\'s trying to turn the solenoid off you should find it has very high resistance between the pin and -Ve. Testing in that way shouldn\'t hurt at all.
I played around last night and measured the voltages as you asked, all the measured voltages with the ignition off was 0v, and with the igniton on I got 12v at 1-5 apart from 6, 6 was a bit strange really, I tested the voltage at the termianl block in the ECU, without it plugged into the ECU if made 12v and when I plugged it in it would fluctuate, possibly the probe wasnt making a good connection?
I also butchered the wiring harness and took the solenoid out of the circuit and ran it directly from the EGI relay and the terminal on the ECU, no joy their either, exactly the same voltages but it would not activate the solenoid. I also checked for continuity from the ground terminals on the ecu harness a ground point and that was fine.
I also tested without the solenoid connector just incase that was broken, same result.
I checked the pins on the ECU for they are fine.
so! what does all this mean :)
1) Broken Terminal ECU Connector (the yellow bit!)
2) Broken ECU
3) Could the ECU be in some sort of strange mode because it reported the charge control solenoid fault, and now it has disabled that solenoid?
Bugger!
James
Nice one, that helps a lot. The ECU could be broken, but there\'s an easy way to test that. Set your meter to test resistance, and measure between the turbo control pin and battery -Ve. Let me know what the reading is.
There will be some kind of transistor in the ECU for each of the solenoids. It is possible that one has given up, but it\'s unlikely. I think I\'ve got a jap spec ECU I could lend you to see if it helps, but I\'d like not to fall into the trap of blaming the ECU just yet.
1) very possible
2) possible
3) doubt it very much, but they do do some very weird stuff!
You\'re making good progress though. Have you tried sticking a paperclip in the pin of the yellow connector on the loom, and testing for resistance between there and the solenoid connector? It\'s important at this point to test for resistance and not use the continuity function on the multimeter. Anything over an Ohm or two might mean it wouldn\'t work properly. This applies for testing the ECU pin as well. Not sure if that\'s what you\'re using anyway, but just wanted to make sure.
Again, let me know what the readings are. I\'m pretty confident we\'ve nearly cracked it!
OK, ill do that, but I want to solder my wiring loom back up first so its back to into its original state, its a bit butchered at the moment :)
Thanks for your help, I will have some results up tommorow :)
J
Dude, how\'s it going?
Well, I carried on yesterday and im in progress of replacing the B/W cable in the engine bay (from the EGI Relay to the air pump, X05, X07 and the diagnosis connector) because we get continuity from anywhere past the EGI relay to the +12v terminal, even with the 30amp egi fuse and egi relay removed.
What we did before was just cut into the B/W cable and replace ran a new one to the X-05 connector and kept the original wiring for the air pump and diagnosis connector, so hopefully once this is all in place I wont be getting continuity to the +12v terminal with the ignition off and I can then check the solenoids again.
Diagram:
http://www.photobox.co.uk/album/album_fullsize.html?c_photo=1345975294
Does the continuity exist because the B/W cable is faulty and connected to ground? Im trying to understand why this state exists! :)
Also, is this an acceptable fix, cutting the B/W cable at each component of the circuit, running same/similar gauge wire and soldering it all together using connectors and shrink wrap? (bypassing the B/W cable)
Thanks,
James
A diagram showing what I think is happening
http://www.photobox.co.uk/album/album_fullsize.html?c_photo=1346055679 (http://www.photobox.co.uk/album/album_fullsize.html?c_photo=1346055679)
James
Quote from: imebgoDoes the continuity exist because the B/W cable is faulty and connected to ground? Im trying to understand why this state exists! :)
Also, is this an acceptable fix, cutting the B/W cable at each component of the circuit, running same/similar gauge wire and soldering it all together using connectors and shrink wrap? (bypassing the B/W cable)
Thanks,
James
Sounds like you\'ve cracked it! Yes, perfect fix. That\'s what I\'d do. See what happens when you\'ve put it all back together. :3gears-rh
Heres hoping it goes back together ok ;)
Lol, we have had the dashboard out to get behind it, pain in the ass if you ask me!
Ill let you know what the result is when we put it back together (wont be until the weekend now!)
James
More problems!
I replaced the B/W cable to the connectors to stop the circuit that was being made when the ignition is off, now it seems the circuit is made with the ignition off when I either connect the 11x2 pin ECU terminal or the X-07 connector.
This is saying to me that the ECU is grounding the 1B pin why would the ECU ground that wire?
The B/W cable on the X-07 connector runs to the EL-Unit, where and what is that?
Im running out of ideas now and I am starting to think im in the wrong area
:(
James
Mate that really sucks.
The Electrical Load Unit should be above the fuse box in the drivers side footwell.
I\'m a bit lost regarding your latest findings though. I take it the car isn\'t in a driveable state?
drivable? lol no
I will check the EL Unit, thanks.
The B/W cable must be going around the car then to that unit, strange I couldnt see it in the harness by the drivers door. Its not easy since the wiring diagram is for a different model. I have replaced the wiring as per that diagram, but it might be that something is different on the B/W cable for the JDM spec and i have wired it up wrong.
Your sure that there definitly should not be continuity from the +12V side of the solenoid connector to the +12V side of the battery with the ignition off? Im checking this by using the coninuity check function on the multitester putting the red terminal on the solenoid connector and the black terminal on the +12V battery. If I swap the terminals around I dont get continuity (eg red on +12v and black in the solenoid) does this have any impact on the test?
I\'ve not given up hope yet.
Cheers,
J
From the diagram I\'m sure that\'s right. Doesn\'t make much sense to be supplying power to the rats nest with ignition off anyway. Ditch the continuity test feature
You\'re not trying to measure continuity while the circuit is on are you? That really won\'t work, and will give very misleading readings!
The only way to measue sensibly while a circuit has power is to measure the voltage at various points around the circtuit, or to put the meter into the circuit and use it to measure Amps.
Also remember that voltage is a difference in potential between two points. You can\'t measure voltage at one point, if you do the reading will always be zero. You have to state and measure voltage with respect to another part of the circuit - usually the zero volt point. This is normally assumed when talking about all things electrical, but almost always forgotten.
Ok, maybe I am misusing the multitester then and its confusing me with respects to the circuit diagram!
I will go through the circuit again with a bit more care checking the voltage when it stops raining.
Thanks again!
J
Ok, i\'ve gone full circle on this, back to the testing the voltage at the solenoid connectors
The double throttle solenoid is active, and that reads +12v at the +12v side and 0v at the - side.
The Charge control solenoid reads +12v on both sides. So, what can this mean?
Does this mean that the solenoid is NOT being turned on by the ECU? (continuity exists between the ECU terminal and the socket)
:confused: :confused: :confused: :confused:
If the wire to the ECU has continuity and measures something like 0.01 ohms in resitance, then the ECU can not be turning the solenoid on?? Either a problem in the ECU or a Ground issue after the ECU??
I need to know the next place to check! :)
Thanks,
James
12V on both sides of the charge control solenoid means that the ECU isn\'t activating it. You\'re on the right track. Can\'t be an ECU gounding issue, as this would affect all the solenoids. Did you over work out if the charge control is supposed to be on or off when you turn the key on?
From what you\'re saying the circuit is now behaving like it should. What happens if you swap the double throttle solenoid connector onto the charge control solenoid, and vice versa?
Here is a quick lesson in electricity for anyone who subsequently reads this thread and needs help working out what is supposed to be happening in the circuit:
A bit of roleplay:
You are now the part of the ECU that controls the charge control solenoid. Your job is to connect the wire leading back from the solenoid to GND to make the circuit when needed. So, when you want to turn the solenoid off, you disconnect the wire from GND.
Now, think about the circuit. When you\'ve got the wire connected current flows through the coil of wire in the solenoid doing work against the spring and now holds it open.
In this state the voltage over the two pins in the solenoid will be 12V. In doing the work against the spring 12V has been \'dropped\' over the solenoid.
I=V/R
I=current (AMPS)
V=Voltage (VOLTS)
R=resistance (OHMS)
So, for the solendoid:
V=12 V
Resistance=50 Ohms (assumed)
So the current = 12/50
= 0.24 AMPS
I\'m sure you\'ve seen this before. We can now calculate the power using:
W=IV
W=Power (WATTS)
12*0.24 = 2.88 Watts
We can call this the ON state.
Now disconnect the wire. The pin connected to the 12V supply will still be at 12V. Think about this next bit very carefully. What voltage will be other pin be at? The answer is 12V.
This may seem weird, but there is a very good explanation for it. The two pins in the solenoid are connected to either end of a coil of wire. If you hold one of the ends at 12V, and leave the other unconnected not a lot will happen. We don\'t have a complete circuit, and no current flows, no work is done by the coil, so we don\'t \'drop\' any voltage over it. The unconnected pin will be at 12V because it is connected the the 12V supply through the coil of wire, and there is nothing to hold it to GND to make a difference between the pins, which makes the current flow, so no work can be done.
Using the above equation again:
I=V/R
0/50 = 0
W=IV
0*0 = 0
Again, no voltage drop, no current. No voltage and no current, no power.
We can call this the OFF state.
OK, your explanation makes sense to me, but, why doesnt the Voltmeter complete the circuit to GND? (i assume we are testing the circuit from the - side to the - terminal of the battery?)
Aside from that and in response to your other questions, swapping the solenoids results in the same as they both work
One thing that is happening is, if we wobble the ECU around the solenoids click off/on (the ones that were on in the first place). This must be a ground issue becuase they all click on/off (no response from the charge control)
Charge control should definitly be on from idle until the secondary turbo change over, I can not verify if it should be on when the ignition is on with the car not started though (one would assume it should be!)
I need to verify how the ground connection is being made, from the wioring diagram on page Z-32 it would indicate that pins 4C, 4A, 4B go to ground at grounding points ontop of the block these are both connected to ground points. Could the solenoids that are functioning correctly not share the same ground as the ones that are not?
More investigation needed.!
J
Quote from: imebgoOK, your explanation makes sense to me, but, why doesnt the Voltmeter complete the circuit to GND?
That\'s because voltmeters are always high resistance, in the order of millions of Ohms, so hardly any current can pass through them. It\'s designed so that it doesn\'t interfere with operation of the circuit you\'re measuring.
Quote from: imebgo(i assume we are testing the circuit from the - side to the - terminal of the battery?)
Yup.
Quote from: imebgoAside from that and in response to your other questions, swapping the solenoids results in the same as they both work
One thing that is happening is, if we wobble the ECU around the solenoids click off/on (the ones that were on in the first place). This must be a ground issue becuase they all click on/off (no response from the charge control)
OK, that\'s interesting. Try running a nice big grounding wire between battery -Ve and the ECU case. If wiggling it now doesn\'t mess things up then you\'ve cured any grounding issues you may have. If not, you might have a dodgy ECU connector, a dry solder joint on the board etc.. If you want me to send my spare Jap ECU PM me your address.
Quote from: imebgoCharge control should definitly be on from idle until the secondary turbo change over, I can not verify if it should be on when the ignition is on with the car not started though (one would assume it should be!)
I need to verify how the ground connection is being made, from the wioring diagram on page Z-32 it would indicate that pins 4C, 4A, 4B go to ground at grounding points ontop of the block these are both connected to ground points. Could the solenoids that are functioning correctly not share the same ground as the ones that are not?
More investigation needed.!
J
That\'s a tricky one. Did you try measuring the resistance between the ECU pin that activates the charge control and battery -Ve? You won\'t hurt anything if you do this, just be careful not to short it to any other pin on the ECU.
Measure the ECU pin for the double throttle as well, as this is clearly working - you should find that both will measure very low resistance to -Ve
Ok, will do that tonight.
As for the offer of the ECU, thanks, that wont be needed, this is my friends car, and I have an apexi on mine so when I get around to getting it out of storage I will donating mine if its required ;)
When you talk about grounding the case, I guess you talking about the bolt on bit that connects? How can we be sure this is the ground for that part of the circuit, why wouldnt it be the ground wires coming out of the pins?
Im also going to pull the engine harness out and inspect - do you think this is an easy enough job? I can just pull it through the firewall cant I?
James
Yup, you can pull it through into the bay without too much trouble, and a bit or ranting about what an annoying place the ABS unit is in :Giggle
It should all amount to the same thing with grounding. The case is attached to the chassis which is attached to the battery -Ve. It might attached through the loom to the engine as well, but this is also attached to the chassis, and the to the battery -Ve, so we end up with the same thing. Or that\'s the theory anyway....
I\'m happy to talk to you on the phone if you think it might help. I\'ll PM you my number if you want
Cheers!, If you want PM me your number I can phone you this evening when im front of the car and I can go through whats going on ;)
Cheers,
James
Can\'t PM you for some reason, so get me on 01256 881114
Ok, cheers,
I had a look around tonight before it started really bucketing it down. Else I would have given you a ring!
I have pulled the wiring through the firewall to test and inspect the wiring easier than breaking my neck down in the footwell.
I measured some resistance:
ECU Charge Control Solenoid Pin to -Ve with everything connected: 30 ohms If the circuit was broken should the resistance be much much higher?
Ground Pins on ECU Terminal to -Ve 4ohms (sounds a bit high for what essentially is a length of copper cable?)
Please tell me im heading in the right direction ;) lol!
James
I take it that was with ignition on?
the 4 Ohms sounds just about acceptable, but it might well be worth adding some extra grounding just to be sure.
30 Ohms sounds a bit on the high side though. I don\'t actually know what resistance the solenoid coils are, but it won\'t be high.
Can you measure one without anything else connected?
If I\'m right in assuming that the coils are around 50 Ohms, then having 30 Ohms in series with it in the circuit might well cause problems, as only slightly more than half the voltage would be dropped over the solenoid - the rest being dropped over the ECU before finally getting down to -Ve
The problem would be even worse if they\'re lower than 50!
Can you measure a few sols on their own and let me know what their resistance is?
Do you get the same resistance to -Ve for ECU pins that actuate other sols?
Would be good to have a reading for the double throttle, which should be active, and something that should be inactive.
You\'re definately headed the right way now!
I think im missing something here, the 30ohms i measured was from the pin in the ecu to ground, how could that reflect the resitance of the solenoid coils? I am measuring after the solenoid, does this take into account the resitance of the enitre circuit?
To clear things up do you want me to measure resitance over the working solenoid terminals when connected?
James
"If I\'m right in assuming that the coils are around 50 Ohms, then having 30 Ohms in series with it in the circuit might well cause problems, as only slightly more than half the voltage would be dropped over the solenoid - the rest being dropped over the ECU before finally getting down to -Ve"
There is not voltage drop over the solenoid? Im mis understanding again!
are you saying that the total resitance of the circuit is 80ohms so it must drop 12v over the 80ohms which must mean that over the solenoid (50ohms) it must drop a proportionate amount of 7.5v? How does that reflect the 12v at both terminals? LOL I wished I payed attention in physics!
I may have to phone you tonight if its good weather!
Thanks.
James
Quote from: imebgo"If I\'m right in assuming that the coils are around 50 Ohms, then having 30 Ohms in series with it in the circuit might well cause problems, as only slightly more than half the voltage would be dropped over the solenoid - the rest being dropped over the ECU before finally getting down to -Ve"
There is not voltage drop over the solenoid? Im mis understanding again!
are you saying that the total resitance of the circuit is 80ohms so it must drop 12v over the 80ohms which must mean that over the solenoid (50ohms) it must drop a proportionate amount of 7.5v? How does that reflect the 12v at both terminals? LOL I wished I payed attention in physics!
I may have to phone you tonight if its good weather!
Thanks.
James
Got it in one! For the pin ON state, I\'d expect resistance to be much nearer 0 Ohms. For the OFF state I\'d expect it to be 1000\'s of Ohms, if not 1000000\'s of Ohms.
You might remember from school an experiment which involved putting a light bulb in a circuit with a switch and a battery, and connecting a volt meter and an ampmeter in the circuit so you could see what was going on? Then putting another bulb in in series with the first, and observing that they both glow, but much dimmer than just the single one. This is because each bulb only has 12/2 (we now have two resistive elements in the circuit) volts dropped over it.
This is exactly the same circuit, except the switch is the ECU and the solenoid is the bulb. What you\'ve found it that there is a resistance through the switch, so we can think of the circuit as being a switch, a resistor, and a bulb all in series. The switch should have about as much resistance as a piece of wire - almost nothing for our purposes, but your reading suggests otherwise. Whilst it\'s not a mechanical switch in the ECU - it will actually be a transistor - it should show very low resistance when it\'s in its ON state, and letting current flow through it.
If you\'re still a little confused, wikipedia probably has some good info about circuits, and will probably explain things much better than me!
It\'s one of those bits of knowledge that if you dont use often you\'ll probably never remember. I only retain it because I do a lot of stuff with electronics, and it still confuses me sometimes.
I should be in this evening, so feel free to give me a call.
OK, Im with you on all this.
But what does this point the problem too? We know there is too much resitance over the ECU which is casuing the circuit to not draw enough current to do the work for the solenoid? right?
So, the ECU is screwy, or the ground is bad?
J
Swapped the ECU for one out of mine and the charge control solenoid works!
LOL!!!
All that for an ECU Swap :flamed
Thanks for your help, I have learnt a lot about the electrics of the car and hopefully should have it on the road again soon.
James
Dude, that\'s really cool you got it fixed. :Thumbs-up Glad I managed to be of some help.