Mechanics

WILL NOT START

2002 Nissan Altima

Computer problem
2002 Nissan Altima 6 cyl Two Wheel Drive Manual 98,000 miles

Friend of mine convinced me that we could take care of replacing the clutch in my wifes Nissan Altima 3.5 SE. After 8 hrs of work he bugged and left me hanging. I persevered and finally completed the work (would never do it myself again) after almost two years. Funny how a 2001 altima is so much different that the 2002. Trying to remove a subframe and getting an engine hoist to hold the motor up while I completed the work were a few of the " surprises" that I had. The worst was finding out that the transmission had been a junkyard tranny (thanks Car Max for letting us know) Car only had 98K on it when the transmission slipped.

Of course that isnt the problem. After two years. I thought I was finally done. Nope. Car will not start. Had a mechanic friend come over with his OBD II sensor. Everything checked out. No codes or problems. Changed the camshafts sensors (front and back) and the crankshaft sensor. Car still wont start. Checked the leads to the coil packs to make sure that they were getting juice. Tried cranking the car while checking the leads. No signal to fire. He had a light he could hook up to the coil pack in place of the spark plug and no light. So my problem seems to be that the coil packs arent getting a signal to fire or all 6 coil packs are bad. The latter seems highly unlikely, and the former I dont know what the solution is. Is it possible I need new computer? Thanks for reading my long post. After all I have done I figured you would want to know everything that I had done. Thanks again.

Dave
Avatar
Dnapkiv
December 4, 2009.



Well to me it simply sounds like you just didnt hook something up or maybe pinched a wire during your repair.

Check at the ignition coil with key on you should have a constant +12v to on the positive terminal of the wire harness. With engine cranking you should have a -12v pulsing signal.

What was the conditions you worked on it. Is it possible the ignition module got moisture on it or any other sensors got wet? Smashed?

Blackop555
Dec 4, 2009.
Ive gone thru everything about 25 times. The mechanic who had his OBD II checking everything said that he was reading everything. That the car should have started.
Ill check yet again on the ignition coil. We were getting the 12V constant(or there abouts) on the wiring harness. We were not getting the -12V pulse though.

The car has been in my garage the entire time so moisture I wouldn't think was the issue.

As for the wires for the engine, well we left them totally intact. We never disconnected any wires from the motor, just removed the battery. The only sensor for the transmission is that of the crankshaft position sensor and it has been replaced.

Thanks for the response. Hopefully you can help me track this down.

Tiny
Dnapkiv
Dec 4, 2009.
Trace that wire. Next step would be if you not getting the -12v pulsing and the wire for the pulse has been tracked is good is to clean up the terminalls on the connector for the ignition control module and check those wires. If not its time to test the icm

Blackop555
Dec 4, 2009.
How do you check the ICM? I am assuming this is the ignition control module.

Tiny
Dnapkiv
Dec 6, 2009.
It is. How would you rate your electrical skills?

Blackop555
Dec 6, 2009.
1-10. Probably a 6

Tiny
Dnapkiv
Dec 6, 2009.
Might be best for your mechanic friend to do this because we wouldnt like to fry your computer now would we?

Turn ignition on and backprobe the ECM and measure the voltage between ground and ECM harness connector terminalls 110 and 112 (red/green wire) if battery exists proceed to next step. If no voltage check for power supply to ECM.

Bacprobe ecm measure voltage between ground and ecm harness terminall 31 (red wire) if voltage exists proceed. If not check power supply for ecm

Turn ignition off and disconnect 116 pin ecm harness connector. Disconnect the intelligent power distributon module 12 pin harness and e122 connector. The power distribution module is located at right front corner of vehicle. Check for continuity of red wire between ecm harness terminal 31 and power distribution module harness terminall 35. Should have continuity. Check for short to ground or short to voltage. If find a problem leave connector harness disconnected and go to next step. If no problem found. Have power distribution module tested or replaced.

Check for loose corroded and damged connections on inline harnesses e27 and e130 check for poor loose and coroded between e20 and e32 as well. And as always check for open or shorts between circuits of ecm and power distribution module

repair as needed.

Turn ignition off and check continutiy in black wire between ground and ignition coil harness of each coil terminal 2 should have continutiy. Check for harness short to voltage.

Check for loose damaged corroded connections on harness connectors f43 and f201. Check for open or short between ignition coils and ecm.

Check for coninutity between igniiton coil harness connector terminal 1 and ecm harness terminalls 5, 6, 7, 15, 16, 17. Shoudl have continuity at each. Also check for short to ground or voltage.

Check ignition coil with power transistor.

Resistance on condensor 2 pin harness connector should read 1m/ohm @ 77degrees Fahrenheit

disconnect coil 3 pin harness connector measure resitastence between spec. Terminals.
1 and 2 should be infinit or except zero
1 and 3 shoudl be except zero
2 and 3 shoudl be except 0

Blackop555
Dec 6, 2009.
Ok. Yeah. Im pretty good with the electrical stuff. But I think Im gonna have that mechanic friend come over and test that stuff. Thanks for the post. I hope this helps my issues. I will get back to you when I have completed this. Thanks Again,

Dave

Tiny
Dnapkiv
Dec 6, 2009.