Exterior Lighting

Refer to PDU User Guide

The complexity of the electronics involved with the various Electronic Control Modules and the two 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 exterior 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. Each switch provides a signal to the Body Processor which interprets the signal as a request to switch on a specific lamp.

The Body Processor places the instruction onto the SCP Network. The module which is closest to the specific lamp, for example, the Security and Locking Module will translate the request which is currently on the network and switch on the rear fog lamps (also controls the reverse lamps). The remaining rear lamps and front 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). The door hazard lamps are controlled locally by the relevant Door Module.

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