ECM resetting/cutting off...Need help from the experts

[SlickTR]

I have an occasional issue with my GN. Mostly when going full throttle or close to it, it will suddenly hit a wall and die or almost die. The car has also died while just driving normal a few times. Doesnt happen all the time but seems to happen everytime I have a nice kill lined up . I noticed on my Direct Scan that when this happens the ecm cuts off for a second and all the settings in the chip get reset. I've already swapped ECMs and that didnt help. I looked at all the grounds I know of and looked at all the wires going to the ECM and nothing looks frayed or loose. Cleaned all the connections. I'm lost and need help to fix this asap. Has this happened to anyone else before? Could it be the chip?

 

[terik.m]

check and see if your dp is pinching your positive battery cable going to your starter. other than that check and see if you have a water leak near the ecm. water caused similar problems on my TR's computer.

 

[SlickTR]

Definately not any water, I've been all through there looking at every single wire lol...I checked the negative and checked the connections on the starter but I dont think I checked the positive cable going back to the starter all the way back; It is quite close to the down pipe as I recall...I will check it later this morning and report back.

 

[TurboDave]

Direct Scan is notorious for causing just such issues. It happens when the connector gets pushed too far onto the ECM. Imperfect connection cleaning can also do this.
Pull the connector, clean the ecm connector reall good, and before re-connecting, get a real small zip tie, cut it to length so you can slide it down inside the DS connector then slide onto the ECM.
Having something down inside the connector will help prevent it from sliding on too far.

 

[SlickTR]

Positive cable to the starter looks fine...Dave, I already cleaned the connector and where it connects really well. It is possible that it's getting pushed on too far as I dont have a ziptie in there, I'll do that later, however I'm always careful not to push it on too far when I connect it. In case this is not the issue do you have any other ideas?

 

[$1987 GN$]

Dave is most likely correct.

If none of these correct the problem; monitor the ECM line in the car coming from the battery for voltage change while flexing the harness near the firewall engine side.

I have seen it broken just before the grommet into the cabin.

If it is you have two ways to fix it. Run a new line in or open the harness and repair it.

Later AJ

 

[JayC]

Make sure the lug on the starter for the hot wire isnt at some odd angle that causes it to hit the heatshield under WOT. Ive seen this a LOT. Car just cuts off and dies.. soon as you lift, it comes back.

 

[WSLN 6]

I had a bad orange ecm wire connector under the hood cause the same issue.

 

[JayC]

I had a bad orange ecm wire connector under the hood cause the same issue.

What the OP hasnt mentioned is if the whole car is losing power of it the engine is just dieing. If its a battery cable issue, the whole car will lose power. If its an ECM issue, just the engine will die. That should help you narrow it down.

 

[SlickTR]

What the OP hasnt mentioned is if the whole car is losing power of it the engine is just dieing. If its a battery cable issue, the whole car will lose power. If its an ECM issue, just the engine will die. That should help you narrow it down.

Just the ECM from what I can tell, car usually stays running, havent noticed anthing else like lights going off. It just hits a brick wall, like massive spark blow out. While logging a few runs when this happened I saw that the ECM went blank for a second and then came back but all the chip settings were reset...I did the zip tie thing and will look at the angle of the starter wire. I will monitor it and see if it happens again with the ziptie in the computer wire and let up guys know what happens.

 

[Chuck Leeper]

At 1 time were there not issues with the DS cable picking up elec interference? Seems I recall a fix was made for a cover for the cable....

 

[JayC]

You can actually wrap the cable from the ECM to the DS in aluminum foil. That helps.

 

[mikestertwo]

Try disconnecting the DS cable from the computer and see if the issue still occurs. If it does then you have a power problem to the computer. If it doesn't, you found your problem.

 

[SlickTR]

At 1 time were there not issues with the DS cable picking up elec interference? Seems I recall a fix was made for a cover for the cable....

Is that something that would just start happening out of the blue when it's been fine for two years? Or happen occasionally and not everytime?

 

[SlickTR]

Went WOT this morning and it happened again only this time the ECM didnt reset but threw some random codes (TPS high TPS low and O2 sensor) then if I went more then part throttle the engine would cut out and check engine light come on like my chip's Valet mode was engaged. I pulled over and shut the car off and then restarted it and it drove fine but then I noticed that the ECM had reset again...I'm almost positive that it has occured with the DS cable unplugged, I will unplug it and see if I can get it to happen again.

 

[aminga]

Grounds?

 

[SlickTR]

Update...looks like it was in fact the DS cable getting electronic interference. It's weird that it just decided to start doing it when it never did it before. Anyway it ran like a top without it plugged in. I wrapped the cable in aluminum foil then a layer of some aluminum backed tape from Lowes and so far so good, no more issues with it pugged in. Thanks guys!

 

[WSLN 6]

Good deal, I did the same thing with the foil, then taped the end of the foil to the ecm case.

 

[Bigjack7440]

That's what my car was and sometimes still does. I remember the day I got the car I had to change the starter I installed the mini one . I bet I need to go check the wires. Like I said it only does it at the end of the run and the radio ,lights,engine goes dead just for a second then as soon as I let off it comes right back to life. Thanks

 

[greeneyegi]

At 1 time were there not issues with the DS cable picking up elec interference? Seems I recall a fix was made for a cover for the cable....

i know this is an old thread,but seems to be the exact issue i have,gotten real ,real bad.can you please explain this DS cable exactly?