B1520

Diagnostic Chart:

Schematic:

CIRCUIT DESCRIPTION
The instrument panel cluster (IPC) connects to a remote switch circuit that allows certain functions to be performed when depressed. The PC monitors these circuit voltage levels and detects when a certain button has been depressed by the voltage drop. If the voltage is not within range for pre determined amount of time, the PC detects the malfunction and sets a DTC.

CONDITIONS FOR RUNNING THE DTC
The IPC and the reset switch must be active.

CONDITIONS FOR SETTING THE DTC
The IPC detects the reset switch input low (shorted to ground) for more than 60 continuous seconds.

ACTION TAKEN WHEN THE DTC SETS
When the PC detects the code as current, it disables (ignores) the reset switch therefore the correct status of the switch will not be known when requested through the DLC.

CONDITIONS FOR CLEARING THE DTC
The PC does not detect a failure during the diagnostic self test after the ignition has been cycled.

DIAGNOSTIC AIDS
The IPC will store the code as current only as long as the failure exists. An intermittent failure will be stored as a history DTC.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
4. Tests for a short to ground in the signal circuit.