Operation CHARM: Car repair manuals for everyone.

PCM Power-Down Routine

After ignition has been turned Off, PCM updates records such as malfunction history and adaptives prior to powering down. If PCM is commanding coolant fan On as a result of elevated coolant temperature, this routine will wait until timed fan run-on is completed (approximately 2 minutes). The actual power-down routine will complete within 10 seconds. If PCM is being reprogrammed (flashed), PCM will stay alive until reprogramming is complete.