Interior Lighting

Tests Using the Portable Diagnostic Unit

Refer to PDU User Guide

The complexity of the electronics involved with the various Electronic Control Modules and the multiplexed communication networks, preclude the use of workshop general electrical test equipment. Therefore, reference should be made to the PDU User Guide for detailed instructions on testing the interior lamps and circuits.

The PDU systematically tests and analyses the lamp assemblies, the bulbs and the electrical connections to them. It should be noted that the lamps are not wired directly to the switches.

The lamps are controlled directly by the Body Processor (it has a sufficient number of high power output stages to drive the lamps/relays compared to other modules) except for the door guard/puddle lamps and the rear passenger reading lamps.

The Body Processor Module receives messages on the SCP network from the door modules relating to door ajar/closed/locked status, sensed by the door courtesy switch(es).

Where a fault involving a lamp is indicated by the PDU, before replacing suspect components, some basic diagnostic methods may be necessary to confirm that connections are good and that wiring is not damaged.