Diagnostic Procedure

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

Fig 1: DTC P2120: APP Sensor 1 Circuit Malfunction (Steps 1-9)

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC P2120: APP Sensor 1 Circuit Malfunction (Steps 10-16)

Courtesy of GENERAL MOTORS CORP.

Fig 3: DTC P2120: APP Sensor 1 Circuit Malfunction (Steps 17-26)

Courtesy of GENERAL MOTORS CORP.