Ok. I'll keep looking for a possible fix.
On a positive note, I've all but verified that it's just my scanner than won't connect via OBDII. I plugged in bradr's ABS Eliminator and it worked like a charm, so the communication is definitely there.
This only tells you that you have communication up to the BCM. The ABS eliminator does not communicate with the PCM. If your OBDII scanner will not communicate with the PCM, you likely still have an issue.
- Did the "Power Steering" Message get resolved?
- Are you seeing an accurate coolant temperature in the instrument cluster?
I do not know. I have not run it long enough to see.
No need for the engine to be running. Does the coolant temperature show something close to room temperature when the ignition is on, engine off?
The coolant temp sensor is wired to the PCM. The temperature is communicated over CANbus to the BCM, then the BCM sends it to the cluster on the single wire CANbus. I think that the display will read "--" for the temp if the PCM is not connected. I will need to verify this on my car when I get a chance.