Diagnostic Aids

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a wire broken inside insulation. Check for following:

• Poor Connection - Inspect ECM harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection and damaged harness.
• Intermittents - If connections and harness are okay, connect a digital volt-ohmmeter (10-megohm) between ECM terminal R10 and ground. Monitor DVOM while moving related connectors and wiring harness. Voltage reading will change if failure is induced. This may help isolate malfunction.

Fig 1: Code 41, Schematic, Cam Sensor Circuit 3.8L

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code 41, Flow Chart, Cam Sensor Circuit 3.8L

Courtesy of GENERAL MOTORS CORP.