DTC 021
CIRCUIT DESCRIPTIONThe Body Control Module (BCM) controls the courtesy lamps through the courtesy lamps feed and return circuits. Battery voltage is applied through the courtesy lamps feed circuit. When the BCM sees the proper inputs it will ground the courtesy lamps return circuit, and the courtesy lights will illuminate.
CONDITIONS FOR RUNNING THE DTC
The BCM must command the courtesy lamps ON.
CONDITIONS FOR SETTING THE DTC
^ The BCM detects that the output for the courtesy lamps feed circuit is low when it is expected to be high.
^ The condition above must be present for more than 0.3 seconds.
ACTION TAKEN WHEN THE DTC SETS
The BCM stores DTC B21/31 in memory.
CONDITIONS FOR CLEARING THE DTC
^ A current DTC B21/31 will clear if a short to ground or open in the courtesy lamps feed circuit is no longer detected by the BCM.
^ A history DTC B21/31 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present and no other BCM faults are detected.
DIAGNOSTIC AIDS
^ If the DTC B21/31 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent and Poor Connections in Diagrams.
^ The following conditions may cause an intermittent malfunction to occur:
- An intermittent short to ground or open in the courtesy lamps feed circuit
- The courtesy lamps are intermittently shorted to ground or open
- The BCM is intermittently shorted to ground or open
TEST
