My sister-in-law has a 1995 Bonneville SE 3800 II. The check engine light has been on for almost as long as they have owned the car which is about 3 years and it lacks power considerably compared to another bonneville that I drove of the same make and model. I have a code scanner that we use on our vehicles to check for codes but when I connect it to the car it just says that it cannot make a connection. She took the car to AutoZone to have it scanned but there scanner said the same thing. I feel that the ECU is bad and that the car is in failsafe mode and has been for a while. I want to check the wiring for the ecu but the book that we have only has basic electrical schematics and nothing for the ECU. Does anybody have the electrical schematics for the ECU on a 1995 Bonneville that you could post or email me? My email is dani9678@bellsouth.net
Thanks.

Your car is a hybrid PCM in between OBD1 and OBD2. Most people at Autozone aren't 'educated' enough to know this.

You need a scanner capable of reading OBD1 PCM'* with a 16 pin cable. Not easy to find. Post your location, we may have someone nearby that can pull the codes for you.

Your username being your email address is a VERY bad idea. Spambots search the internet daily for email addresses. This is giong to be bad for your inbox in a very short period of time.

Please re-join the Forum with a different username, and post here again. I'll delete your old profile.

I am in Zephyrhills , FL. 30 minutes north of Tampa.
I disconnected the ECU after the battery was removed to see if it may have burned up or had an internal fuse and found an access cover on top which covered a removable chip which I removed then I reinserted, reconnected the computer, intalled the battery and now the car will not start. What happened?

I tried rejoining but it says that my email is already taken.

help.
:(

Did you disconnect the battery before unplugging the computer?

Yes, The battery was out of the car about an hour before the computer was removed.

Is the starter turning over the engine?

Yes, the engine spins over nice. I put a spark tester on one of the coils but got no spark.

Check all the fuses under both sides of the dash.
Check for spark at another coil.

I pulled out the rom chip (I believe) from it'* socket on the main board of the ecu and reinserted it after I removed the ecu from the car. Do you think that could cause a problem. I made sure to only grab the blue plastic part of the chip so not to short it out.

P.*. Do you think that the crankshaft position sensor could cause the no start? It was removed when we removed the timing cover and replaced the harmonic balancer.