I am having problems with the 92. I can't keep it running. When I start it the Sys and security light blink sometimes the car will startand run but most times it will start ans shut off right away. I will turn the key off and try again and it will shut off. I will let it sit for awhile and it will start and run ok but every 15 seconds the SYS and Security light will blink for 5 seconds and they go off. This is driving me crazy. Does anybody have any answers as to what the problem may be.
Thanks

 

Had the same problem-Bad ECM(engine control module). Replaced at the dealer, although it took almost a month for them to get it from AC-Delco.

 

Pull the codes and tell us what DTCs are present.

http://www.c4guru.com/articles/CCMCodePull.pdf

The reason it is starting and dying is because you have a current occuring DTC and it has enabled FEDS (disables fuel).

 

I don't know if this has anything to do with my problem or not but while driving the ASR light comes on also.
Thanks

 

Yep most likely a CCM DTC 41 ECM Serial Data Circuit (lost communication), you may also have a DTC 71/72 I think it is for Display errors (paraphrased) basically the two computers (ECM, EBTCM, CCM) are not communicating with the CCM at the required time interval. The CCM is primary all others are it's slaves.

Could be a short, could be a faulty ECM; most likely it is the latter.

You need to pull the codes. All this is just guessing.

 

Before I had the ECM changed, it was also showing the ASR light.

Sounds like deja vue for me as the cause being a bad ECM.

 

Thanks guys for your input, Where's the best deal for an ECM?

 

I just got the sys/security problem yesterday.. I was driving along and all of a sudden the security light started flashing and the "service asr" light came on. I was afraid my car was going to do something unexpected while i was driving, so i pulled over, and popped the hood to take a look. I tried starting my car again, but my car would start for about 1 second and then immediately die. Kept trying, then eventually, car wouldn't even start. I tried pulling codes (only tried to jumper A-B ALDL),I guess i fiddled with the CCM connection too, because i tried starting my car again after a few minutes and it fired right up. Drove the rest of the way home (sys/security light started flashing again) I got home, went to grab my FSM's. After a little research in the FSM and DTC troubleshooting (received codes 41, 54 (FEDS - "Fuel Enable") , and another .. code sixty something. (LED dimmer)). According to the FSM, a likely cause is just a bad CCM connection. it turns out that if there is ever a communication error, the car will continue to run, but the CCM will disable fuel (FEDS) if you turn off the car. I never should have pulled over and shut off the car.

.I checked the CCM connections to make sure they were firmly seated.
This weekend i may have to pull off the CCM and inspect all of the connectors. But for now, my car is back to normal.

 

Check your battery.

 

VetteUSA where is the CCM located, how hard is it to get to. I also have been having a SYS flashing but not security. DTC 41

 

The CCM is located behind the center console. It is tucked in there very tight. Access is done by removing the driver's side of the console, lower knee bolster and bracket on the drivers side. Then several hours of carefully coaxing it out. It sits on the connectors so you must be really careful so as not to damage any wires. It also helps to remove the console trim, radio bezel and radio to have a extra hand access to it. (I didn't do the latter but realized at another time when I had the radio out that would have helped some. The FSM doesn't state to remove it though.)

If you want to see images, I believe I still have images loaded.

Also the whole point from troubleshooting that you would pull the CCM out is the check the continuity between the two serial lines between the CCM and ECM you'll need to expose the pins on both and test with a DVM. While you have it out might as well test the continuity between the BTCM and CCM. Most likely it will be fine and you'll have spend a lot of hours and frustration.

I still believe you probably have a marginal ECM causing the problem. But that is "just a guess."

 

Sounds like something I should leave alone and take to a professional. Thanks.

 

Just clear your DTCs for all modules and see if the DTC 41 returns. If it does then run diagnostics to isolate the cause.

 

Sorry, it was 71 light sensor i think. When the SYS if flashing, I can't change anything with the buttons

 

I'm a little handicapped not having my FSMs any more. The SYS should only be flashing if there is a currently occurring DTC if I remember. So it should stop. But your saying when you enter Diagnostics you can't clear any DTCs?

 

DTC 71 The SYS flashing starts and stops. Sometime, it stops a short time after starting to drive. Sometime, it ttakes several days to stop. I do notice when it's sunny out and I open the door, the inside lights come on. When it is flashing, I can't change anything using the buttons. I know I could not reach the CCM, I had back surgery with some metal in my spine so I'm not able to bend or twist very much under the dash. Thanks for the responce

 

Yeah you have to be a slight contortionist to get under and remove it.

 

Yep, just getting in and out sometime is a problem

 

Sorry, I meant to say ECM in my post.

But a big thanks to Jet-Jock for the additional info on the CCM location.

Also, Just looked at my codes again:

The codes i received were
41- ECM Serial Data Circuit (loss of communications)
54- FEDS Fuel Enable Circuit (Fuel enable failure)
74 - LED Dimming Ouput Circuit (Circuit Open or shorted to ground)

 

If I remember correctly the 41 caused (set) the 54, and the 74 usually appears anytime a data link error occurs.