P1520

Diagnostic Chart:

Wiring Diagram:

Circuit Description
The PCM supplies ignition voltage to the Park/Neutral Position (PNP) switch through the signal circuit. The contacts inside the switch open whenever the voltage is greater than 1v. The Transmission Range position (TR) switch contacts should remain closed whenever the transaxle is in park or neutral. The contacts will open whenever in the drive and reverse ranges.

Conditions for Setting the DTC

^ The Engine Speed is between 1600 and 2800 RPM.
^ The Throttle Position (TP) Sensor is between 7 and 26%.
^ The vehicle speed is greater than 40 MPH.
^ The PNP switch shows P/N without change since start-up.
^ One or more of the following DTCs are not set P0121, P0122, P0123, P0335, P0502, or P0503.

or

^ The PNP switch shows P/N regardless of range selected.
^ The above condition is present for 27 seconds.

Action Taken When the DTC Sets

^ The Malfunction Indicator Lamp (MIL) illuminates after 2 consecutive ignition cycles in which the diagnostic runs with the fault active.
^ The PCM records the operating conditions at the time the diagnostic fails. The Freeze Frame and Failure Records buffers stores this information.
^ A history DTC is stored.

Conditions for Clearing the MIL/DTC

^ The MIL will turn off after 3 consecutive ignition cycles in which the diagnostic runs without a fault.
^ A history DTC will clear after 40 consecutive warm up cycles without a fault.
^ A scan tool can clear the DTCs.

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

1. The Powertrain OBD System Check prompts the Technician to complete some basic checks and store the Freeze Frame Data and the Failure Records on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurs. Refer to this information on the scan tool later.

10. Before replacing the PCM, check the terminals for improper mating broken locks, or physical damage to the wiring harness. Replacement PCMs must be reprogrammed. Refer to the latest Techline information for programming procedures.