Test Description

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

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

3. Clear the DTC in order to verify that the fault is present.
4. Measure the requested torque signal in order to determine if the signal has a valid duty cycle.
5. Measure the requested torque signal in order to determine if the signal has a valid frequency.
11. This vehicle is equipped with a PCM which uses an Electrically Erasable Programmable Read Only Memory (EEPROM). When replacing the PCM, the replacement PCM must be programmed.

Fig 1: DTC C1277 or P1571 Diagnostic System Check (Step 1-7)

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC C1277 or P1571 Diagnostic System Check (Step 8-13)

Courtesy of GENERAL MOTORS CORP.