Conditions for running the DTC

WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

Ignition voltage between 10.5 and 17 volts
Off state test - Initial ignition ON, no engine RPM or vehicle speed present.
On state test - If off state test passes, engine RPM and vehicle speed present.