Test Description

The numbers below refer to the steps numbers on the diagnostic table.

1. 2. This step determines if a communication condition exists.
2. 5. This step isolates an internal APP sensor failure. The condition may only occur at a certain accelerator pedal position. Monitoring the APP angles for sensor 1 and sensor 3 is an accurate way of verifying the actual position of the pedal.
3. 6. The APP sensor 2 shares a common 5-volt reference circuit with the TP sensor 2. Monitoring the TP sensor 2 voltage aids in diagnosing the APP sensor 5-volt reference and low reference circuits. If the scan tool displays near 0 volts, the circuits are OK.
4. 18. When the TAC module detects a condition within the TAC system, more than one TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Disconnecting components during testing may set additional DTCs. Keep this in mind when reviewing the stored information, Capture Info.

Fig 1: DTC P1281 (1 Of 2)

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC P1281 (2 Of 2)

Courtesy of GENERAL MOTORS CORP.