Today I received my K-9 personality key, plugged it in, hooked up the scanner, and told it to read codes. It showed these three "History codes":
341 Intermittent Camshaft Sensor
350 EST Failure
670 QDM 4 Failure
Since they were "history codes", I figured that not all of them may be relevant now. So I told the machine to clear the codes. The only one that came back is 670 QDM 4 Failure. I did a little searching, and found this:
The QDM 4 code is set if any of those 4 lines are open. Obviously it's not the SES line, because the light is on while the key is on. What I'm thinking is, since the car doesn't have a 2-speed fan, maybe one of those fan control lines was left open.
Now here's the strange thing. Notice that the fan fuse is labeled "Cooling Fan/TCC Fuse". Does that mean that the TCC won't work if either of those lines is open?
Looks like I have a job ahead, checking some circuits.