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I have a 1998 Buick Century with a 3.1L and 4T60E transmission. I recently had my transmission rebuilt and since the rebuild the car has a surge/shudder at 40-50 and 60-75 mph. The torque converter is locking up I can tell, and if I press the brake pedal just enough it comes out of lock up. After the transmission rebuild does my PCM need to have the Case relearn procedure done on it? I am just curious because I have had a local shop rebuild my trans twice and I continue to have the same issue. I took the car to another shop, they charged me $218 to check and diagnose the issue and they found a cut wire and after there repair I no longer had the issue. One week later my torque converter started leaking trans fluid from the main seal the original shop that did the 1st two trans rebuilds repaired the leak by putting in new seal and torque converter and again I have the same surge/shudder at 40-50 and 60-75 mph. Note: I have no power to my crank signal BCM cluster in the fuse panel (schematics show them as a purple and pink wires) should I see any voltage there or is the fuse just for protection for the PCM?
12/10/12 – New info, had a shop diagnose the car and they found wire insulation damage. The wires were saturated with motor oil which is conductive. This I beleive was causing intermittent signals/shorts to my PCM causing the shuddering problems I have been dealing with. The shop has replaced the wires with the damaged insulation/oil saturated and will see how the car drives now. I know there is a Mecedes benz model that has had a similiar issue with oil leaking into the wiring harness generating shorts?????
http://mailman.egr.msu.edu/mailman/public/thermal/2001-May/000412.htmlRegards,
Eric B.
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based on the above scenario, it is most likely a bad torque converter from the beginning. A bad TC could have caused all your problems. it is quite possible that there is no electrical issue at all. this could solely be a mechanical failure; TCC shuddering and fluid leakage support this conclusion. your PCM is mostly likely fine. since the TC cannot be rebuilt(it is an enclosed unit)it is recommended that a new torque converter be used with new or rebuilt transmissions in efforts to deter compromising the entire system with debris in case of torque converter failure.
although i am not a chemist, i know that most oils are non-conductive. for example, electric companies use oil in their substations and transformers to keep them cool, lubricate switches, and to extinguish electrical arcing. but a good counter argument could be that water in it’s purest form is also non-conductive; it is the impurities (minerals) that actually conduct current… and i would guess that it is possible that oil could exhibit similar properties, although highly unlikely.
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