Computers and Control Systems: Service Precautions

CAUTION: Electronic modules are sensitive to static electrical charges. If exposed to these charges, damage may result.

1. Always disconnect the battery ground cable before servicing or replacing any electronic engine control.
2. Disconnect electronic engine controls from the wiring harness before measuring for continuity, resistance, or energizing with a 12 volt power source.
3. Never measure voltage or resistance directly at the Powertrain Control Module (PCM).