Car Wont Start - PIM, VTA1 & VTA2 All highlighted on PFC

ttpower · May 17, 2014, 10:20:45 PM

I\'ll try my mates first....if a grounds gets hot that\'s a lot of resistance right

ttpower · May 17, 2014, 10:22:09 PM

If the map was gone, the 5v signal should still continue to tps right

ttpower · May 17, 2014, 10:25:27 PM

Similar scenario to mine: http://m.rx7club.com/showthread.php?t=966924
Might attempt to open and take a look at the board

boosted · May 17, 2014, 10:30:29 PM

If it had a short it would drag the 5v down to 0v. The fact the tps, map are grounded to the ecu at 4D the wiper earth should not effect as separate circuits . With the map disconnected recheck for 5 V on 3I. there was a thread how to check map with resistance.

Hot earth= bad connection high resistance more current.

boosted · May 17, 2014, 10:42:19 PM

mmm..reading that id hold off on putting your mates apexi in ! You gotta start looking for shorts. Unfortunately the 5v is not fuse protected so simply fitting another will solve until this burns out as well. multi meter time...

See if 5V on 3i with map disconnected? Disconnect all sensors etc and see if 5v present ? reconnect each sensor in turn and see if goes off.

boosted · May 17, 2014, 10:57:19 PM

If it was my car i would go to 3I at ecu harness. power off ....with 30mm ish from harness cut cable. strip ecu side and test here to 4D with power on....all sensors connectors wires etc seperated of circuit and see if 5V present. If not defo ecu fried.

Also test other end of 3I to 4D with power off in resitance and see what resistance reading you got. )0 ohms would be a defo short...

cuts out the head scratching and cable can be resoldered.

ttpower · May 17, 2014, 11:40:18 PM

Bloomin genius.....I cut off 3i and I got 5v coming out of the ecu. Resistance between 3i and 4d is .436.
So what\'s next step, installing each sensor one by one and testing volts.

Does this mean there is a sensor problem on that circuit or a grounding issue.

boosted · May 17, 2014, 11:52:13 PM

Sweet... ecu good so sensor wiring or connector taking the 5v down...i think a short mate...this is where the funs starts. Goona have to seperate sensors from loom test with resistance and check ok against values of good 1s which is where your mates car may come in handy.
Then if they all test good wiring. Again resistance test but with sensor connected etc.

boosted · May 17, 2014, 11:55:49 PM

Edit. Test wiring with sensors dis connected after sensor test. Need to protect the apexi now as this could still burn the voltage regulator out.

ttpower · May 17, 2014, 11:57:24 PM

So on this 5v circuit there is map, tps, egr, omp & powertrain control module (autos only).

I have no egr & disabled omp. My car is also a manual. So leaves it down to the tps or map sensor or omp plug(not cut this off the loom).

boosted · May 18, 2014, 12:01:21 AM

Yes. Poss short on 1 of them but still could be a connector in loom...

ttpower · May 18, 2014, 12:02:05 AM

So first plug in sensor at a time and check voltage at ecu. Then if that not showing check wiring resistance from the sensor connector to the ecu input

boosted · May 18, 2014, 12:02:27 AM

Me off to bed now. Good luck...use resistance test protect that apexi.

ttpower · May 18, 2014, 12:04:56 AM

The wiring for this is only on the engine harness right. But the short is only within them few sensors supplied from 3i off the ecu?

ttpower · May 18, 2014, 12:05:32 AM

Ok cheers mate, keep u posted tomorrow.