GM Storm/Spectrum 1985-1993 Repair Guide

Clearing Codes


On most vehicles, the TECH1®, or an equivalent scan tool may be used to clear codes from the ECM memory. If a scan tool is unavailable or your tool does not have this capability, power must be removed from the ECM for a minimum of 30 seconds. The lower the ambient temperature, the longer period of time the power must be removed.

Remember, to prevent ECM damage, the ignition must always be OFF when removing power. Power may be removed through various methods. The preferable method is to remove the 30A main ECM fuse from the underhood relay/fuse box. The ECM pigtail may also be unplugged. If necessary, the negative battery cable may be disconnected, but other onboard data such as radio presets will be lost and the ECM may have to undergo a brief relearning period before normal performance returns.