My son was driving my 8 on the freeway at 70 mph (so he said) and hit a bump in the pavement. The back end bouned enough that it came loose. The stability control light came on and also the check engine light. The engine ran at 3000 rpm and he had no throttle control. He shut down the engine and waited about thirty seconds and restarted the engine. At that time he had throttle control, but the check engine light stayed on. Two shopping trip stops later, the check engine light went out on it's own. Could someone more knowledable than me give a scenario on what happened? Did the engine hit a high rpm limit? I've had the stability control activate on slick roads, but it didn't lock the throttle at 3000 rpm.

 

Even though the CEL went out, the PCM will still have stored a code for the condition that caused it. Your dealer's diagnostics equipment will be able to read the stored code.

FWIW - I think your son is BSing you! Stability control intervention will never impose a rev limit or light the CEL. Something else happened. Even bouncing off the rev limiter (@~9500 rpm) won't light the CEL. Maybe he was doing donuts in a parking lot, trying to drift, or something similarly extreme... Your dealer can tell you what the code says - from that, we could offer suggestions as to what your son was doing to trigger it. Perhaps the CEL and throttle limit was unrelated to any action by your son, so I apologize in advance if that was the case.

Regards,
Gordon

 

The 3000 rpm and no throttle control and MIL illumination mean that the electronic throttle went into failsafe mode. It will do that if one of input signals, for example the eccentric shaft sensor, the throttle position sensor, or the accellerator pedal sensor fail, or the signals received from one of them is not congruent with the other sensors.

If everything is working OK on the car now I would guess that when your son had his 'event', the accellerator pedal position sensor was sending a signal that was not congruent with the engine speed/throttle position or maybe even vehicle speed.

I don't know what happened, there may be something genuinly wrong with your car, but it is more likely that the PCM thought whatever happened when your son was driving was impossible. It didn't believe the signals it was receiving from its own sensors, so popped a MIL. Should be fine to drive now (the MIL goes out if there is no problem detected after two drive cycles).

 

Your scenarios fits the event nicely, especially the light going out after two drive cycles. Thanks.