Grounding Question - The Usual TCM Issues
I too have the common TCM issues that result in a wonky speedometer, awful shifting, ABS+traction control failure, and loss of power steering. It started about 2 years ago.
I grounded the TCM outer body to the frame, and replaced the TCM fuses both under the hood and in the BCM box. Voila, problem solved, until now.
Now I just get an intermittent check engine light with the same error codes as before. Disconnecting the 2 fuses and reconnecting them removes the code, but it will return within days. The usual failures don't occur; I just get a check engine light.
I took a multimeter and tested the resistance between the TCM body and the engine block (just left of the oil fill cap). My multimeter gives me:
At 20M ohm: a reading of 0.1
At 200k ohm a reading of 1.
So... 200,000ohm. That seems really high for a circuit that should ground out, right? I checked my makeshift ground, and it's clean (and reads out ~100ohms).