78,xxx miles on a 3.8 2007 Pacifica. Went to clean the throttle body, but the back side of the butterfly plate was sooo heavily caked, the only way to effectively clean it was to remove the throttle body. I took it off the car and removed the plate. After soaking it in solvent and sacrubbing for a while with a rag, got it prefectly clean and reinstalled. Now, the ECT light, a lightning bolt inside backwards parenthesis )(, comes on intermittently, but fairly regularly.
When idling, it comes on for a second every 3 or 4 seconds, and the engine speed surges momentarily (a couple hundred RPMs). When accelerating, or when cruising at a decent speed (45+ mph), the light seems to stay off. But when coasting down, it sometimes comes on as the engine speed drops. It might just blink on then off, or it may stay on for several seconds. Over the course of a 25 mile drive, the car went into limp mode, with the ECT light and the traction control light illuminated. Turning the car off and restarting got rid of limp mode.
I removed the battery cable for 15 seconds and have no OBD codes. No check engine light. I thought this would force a relearn of the throttle position in case that was the problem. I'm out ideas at the moment, and I don't have a dealer around me that I feel I can trust. Help!