B2502

DTC B2502





Circuit Description
With the ignition ON, ignition 1 voltage is supplied to the coil side feed of the PARK relay. The control circuit of the PARK relay is controlled by the body control module (PZM). When the PZM receives a class 2 serial data message from the powertrain control module (PCM) stating that the automatic transmission is in the PARK position the PZM grounds the control circuit of the PARK relay via an internal switch called a driver. The driver supplies a path to ground for the component being controlled. Each driver has a fault line which the PZM monitors. When the PZM commands the PARK relay OFF, the voltage of the control circuit should be high, near battery voltage. If the circuit voltage is measured below the fault line the DTC is set.

Conditions for Running the DTC
Ignition in the ON position.

Conditions for Setting the DTC
The PZM determines that the PARK relay control circuit is shorted to battery voltage.

Action Taken When the DTC Sets
The PZM will continue commanding the requested state until the state is achieved or until the request changes.

Conditions for Clearing the DTC
The PZM determines that the PARK relay control circuit is no longer shorted to battery voltage.

Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
2. Listen for an audible click when the PARK relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests for voltage at the coil side of the Park relay. The CRUISE fuse supplies power to the coil side of the PARK relay.
4. Verifies that the PZM is providing ground to the PARK relay.
5. Tests if ground is constantly being applied to the PARK relay.
6. Test if the control circuit of the PARK relay is shorted.