Sonny_T

Need help!!

Owner of an '85 Transam v8 HO 4bbl Carb, Manual T. G engine'.

Please note car doesn't have 'Check Engine' or 'Engine Service Soon' light. It has a 'Engine Symbol' light. Here are summary of what I have tried:

1. Key off light is off.
2. Turn key on light comes on, doesn't flick and stays on.
3. Car runs, it stays on.

In my ALDL connector:
1. I have no lower pins. I have 5 upper pins and missing pin in upper side is 'E' pin.
2. When I short A and B and turn key on (not start) light stay on.
3. I pulled ECM out (1226865) of the wiring harness, light stays on with key on.
4. With ECM out, AB is shorted, light still stays on.

Light always stays ON, and I am .

Where do I begin! any one! help please!

What is 'lamp driver module' and where is it/or how I check/replace it?

Car runs normal for its mileage.

Thanks.

Sonny_T

Me again!

It doesn't flash/flicks or do anything, no codes, it simply stays on.

I checked 10amp red fuse and it is good.

RBob

iTrader: (1)

Sounds like the lamp driver module may be bad. There is some other info in this thread:

https://www.thirdgen.org/forums/dfi-...ine-light.html

RBob.

Sonny_T

Bob, thanks for the info and I did go to link you provided. I have new battery and alternator is charging battery.

Now:
1. Where is Lamp drive module in cabin/where can I buy it?
2. In my ALDL cable pin E is missing. Is that means I can not download info to my laptop using ALDL cable.

Sonny_T

ECM 1226865 doesn't have serial port, hence my vehicle '85 Transam, HO G' is not capable of connecting to a laptop regardless of cable type. Learning is, if ALDL connector in car, doesn't have any one of 'E' or 'M' pin, you car/ECM has no capability to transmit data to a PC.

Now, I have to have a scanner tool to find out what is wrong/? with my ECM. ECM 1226865 in my car only controls Air mixture control of carburetor, other then this one task, it does nothing as for controlling. Of course it receives information from sensors to provide fault data.

Still do not know where to look for 'lamp driver module' beside this being inside the passenger cabin. I am having issue some where between 'lamp driver module', ECL, ALDL connector and ECM.

Vader

There is a separate driver module on the ECM in this application. The module does the pull-down for the SES lamp. Basically, it completes the ground circuit for the lamp. The power for the lamp is supplied by the GAGE fuse. The module should be in the auxiliary relay panel on the right (passenger) side of the dash. There should be four wires connected, yellow, pink/black, white/green, and black or black/white.

In addition to a failed (shorted) driver, any grounding of the circuit outside the driver (yellow wire) will keep the lamp on as you describe. If you disconnect the lamp output from the driver module and it stays on, the problem is outside the module. Pin "D" in the ALDL is also connected to the ground side of the lamp and driver module output, so any problems with the wiring there can also cause the lamp to remain on.

Standard Motor Products RY-536



If the module has failed there's a good chance the 1N4001 diode is shorted or the TO-92 NPN transistor has shorted E-C. Both can be had HERE but I'm not sure we can afford the 64¢ each to solve this.

Sonny_T

Vader, thank you and I was finally able to find the 'lamp drive module' and it is exactly as your picture shows. As of now I was able to locate and disconnect ECM and 'lamp driver module'. Now I will troubleshoot. I can only work in weekend.

Add to this, do you agree since I do not have pin E or M in my ALDL connector and I am guessing, my ECM then simply doesn't have any serial data transfer capability. It means only way to find trouble code is shorting AB.

I will continue to work on it till there is a resolution.

Thanks again.