pcmhacking.net

Hello,

Hoping for some help here, please, this seems to be the right place to be

The check engine light in my car lit up, wonder how to activate CEL in a safe way or use a scanner of some sort ?
The 10 pin diagnostic port (positioned close to the generator) looks a bit different than others i have seen on-line. It only uses 4 pins, A,B,E,F.

The ECM is labled GM 01227887 (bar-code 001227887359), these numbers is used on other ECM, saw it on ebay, on an ECM for a 1.6L engine, strange, why same number ? The ECM for my car should have a dedicated number ?

Is it a VN,VP,VR or VS -type ? How to identify it, can i see by opening up the ECM, and looking for some specific hardware?
Since it looses fault code when disconnected i wish not to remove it, unless needed.
It seems to be a change in type around 1987/1988 in USA/GM, maybe also in Europe/opel then?

Can i connect pin A to B without damaging the ECM , to activate CEL ?

Thanks,

Anders

Looking at this it shows the Opel 10 pin connector.
https://www.techedge.com.au/vehicle/ald ... connectors

Also some info here
https://web.archive.org/web/20041209084 ... LFLASH.htm


If the connector is the same, yours shows the 8192 baud pin as not present so may only flash out the codes.

Thanks for replying.

On the schematics for my car it states:
A: brown, ground.
B: black-white, goes only to ECM/A9.
E: brown-white, goes to ECM/A5 + CEL.
F: red, goes to ECM/C16 and fuel pump relay.


I can´t find my ALDL-connector on any of the url´s suggested.

If I start picking info from other connectors then maybe E is 160 Baud when A and B is connected with 10 Kohm, and then I can check with an oscilloscope if it is a 5V or 12V signal ?

Thanks,

Anders

Bridge a and b with a paperclip or short peice of wire and count the flashes of the check engine light to get the code should spit out 1 long flash then 2 short 3 times for code 12 then flash any error codes after that 3 times for each efore moving to the next one

I did try the paperclip an hour ago and it worked, got 12 12 12 and 35 35 35 and 12 12 12, so it gave fault code 35, maybe IAC because engine don´t run, only ignition on ?

Sorry to say but the permanent fault code had vanished some days ago, we´ll see if it comes back.

I put a 10k ohm resistor between A-B, and logged signals coming from pin E, see signals in attached picture (seconds on X-axis and volt on y-axis)

It shows signal going from around 0V to 11.75V, so I guess this a 12V system and thus with 160 baud , right?

Thanks,
Anders

Corsa A wrote:...I did try the paperclip an hour ago and it worked, got 12 12 12 and 35 35 35 and 12 12 12, so it gave fault code 35, maybe IAC because engine don´t run, only ignition on ?...

If the code relates to Idle Stepper Motor (or any other codes), the code is flashing because of a fault in the circuitry or wiring, not because of engine not running.

Corsa A wrote:...Is it a VN,VP,VR or VS -type ? How to identify it, can i see by opening up the ECM, and looking for some specific hardware?
Since it looses fault code when disconnected i wish not to remove it, unless needed...

Can you take a photo of the ECM board, now that the fault code is no longer active. Outwardly the ECM looks similar to our '808 ECM.
The fault code will likely reset if the fault is still present.

Thanks for replying.

Are these fault codes applicable for my ECM ? https://web.archive.org/web/20170915123 ... ultec.html
I used no 35 from that list : Idle stepper motor - Poor or no idle speed control.

I can take a photo of the ECM in the car ,C13N from 1987, the next weekend, but I think it should be the same for C13N from -88, of which I have a spare ECM, here is a photo (the chip in the upper part of the blue container is marked 16055805, (2) 8846 ):

Corsa A wrote:...Are these fault codes applicable for my ECM ?
I used no 35 from that list : Idle stepper motor - Poor or no idle speed control...

You would have to find your ECM number that links to a list of corresponding DTC's (trouble codes). That list has many more items than our '808.
If the IAC motor is functional, you will hear it clicking/ pulsing during the Diagnostic check.
Here are two of our ECM's for a comparison:
viewtopic.php?f=7&t=14&hilit=1227808+image

I don´t know if it is a special list you mean? I have tried to search on the web for 01227887 and DTC but couldn´t find any list.

I will check the IAC when I get my car back.


Thanks,

Anders

I found a similar DTC listing (to the list in your post), and it was prefaced with "This fault code chart shows the GM-Multec fault codes for the following systems:- SPi, MPi, CFi, M and S".
Does this help.