Re: 90 Galant ECU(?) problems

Check your pulse generators to the tranny. I had the same set of shifting problems that you described and the trans was completely rebuilt 3 months earlier. I read my trouble codes for the tranny and they pointed to the pulse generators. Under warrantee I had both replaced free of charge but in my case it didn't help a bit. So along with aamco (last place I'd recommend) we were looking at a problem with the trans computer which wasn't under warrantee so I decided to get a used trans computer. Plugged it in and car ran worse than ever -- plugged my original computer back in and now problem is 10x worse. So, to make a long story short, it wound up that the connection to the trans computer was the problem because after inspecting and doodling around with the contacts of the connector harness using a miniature screwdriver the car THEN ran perfect and still does 6 mths later. In retrospect, what I think happened was that when I had a new trans computer installed with the trans rebuild the simple act of unplugging and plugging back in a new computer messed up 1 or more contacts on that connecting harness so I made sure they were all spaced properly and with hardly any tinkering it solved a 3 month problem that nobody could figure out so I would start there as a possible solution. If that doesn't work I would get a trans comp from a scrapyard or from somewhere that excepts returned electrical parts and see if that does the trick. The pulse generators can be checked with a voltmeter and the service manual supplies the how to info. Also, you might have a fuse like I do for the auto trans located in the main fuse box, check that 1st 'cause it'll only take 1 minute to check.

My car is a '91 talon (eclipse) so I can't help you with any specifics for the galant.

Good luck and let me know how you make out 'cause like I mentioned I was experiencing very similar problems that plagued me for 3 months before 'stumbling' across the problem.

Sincerely, Greg

Reply to
Greg
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Greg,

Thanks for the reply.

Sorry for sounding like an idiot:

What are "pulse generators to the tranny?"

How do I read the tranny trouble codes? I have only found directions for accessing a diagnostic port for the main ECU, right next to the fuse box.

Once I get this figured I will definitely write back and let you know how I faired.

Thanks,

Karl

Reply to
Karl Perry

Karl, you are gong to need the factory service manual to decipher what your trouble codes are indicating. I believe a pulse generator 'tells' your trans when to shift and on my car they are located on top of the transmission. In the service manual you would get info on their location and how to test them using a volt/ohm meter. Have you tried unplugging the trans computer and inspecting the contacts and cleaning them and reconnecting very carefully? Maybe when your trans was worked on they had to unplug that thing. My chilton manual doesn't list trouble codes and troubleshooting for the transmission so when I needed THAT information I went over to a library that has the factory service manual for my car and borrowed it (otherwise I would have bought one by now). The chilton does give the location of the trans computer though-- I think.

Good luck, Greg

Reply to
Greg

Karl, I just fixed my '91 Galant which was exhibiting the same symptoms you describe. The TPS - Throttle Position Sensor - was bad.

Andy

Reply to
Andrew Fraser

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