Backup Lamp: Description and Operation

Stop And Reverse Lamps

DESCRIPTION

Stop Lamps
The stop lamps operate when the ignition is switched on and the brake pedal is pressed. The stop lamps will also illuminate when Hill Descent Control (HDC) is operational.

Reverse Lamps
The reverse lamps operate when the ignition is switched on and reverse gear is selected. Operation of the reverse lamps is controlled by the Central Junction Box (CJB) which receives messages via the medium speed CAN bus from the instrument cluster.

OPERATION

Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fusible link 11E and fusible link 16E of the Battery Junction Box (BJB) (C0632) on an R wire. Fusible link 16E (C0570) provides a constant battery feed to the reverse lamp relay (C0583) on an NG wire.

Fusible link 11E (C0570) is connected to the ignition switch (C0028) by an N wire. When the ignition switch is in the 'ignition' position, current flows across the switch (C0028) to the following on a Y wire:
^ Fuse 15P
^ Fuse 66P
^ Central Junction Box (CJB)
^ Reverse lamp relay.

All are located within the CJB (C0582).

Fuse 15P (C0585) provides an ignition feed to the stop lamp switch (C0075) on a GO wire. It also provides an ignition feed to the HDC relay, which is also located within the CJB. Fuse 66P (C0582) provides an ignition feed to the stop lamp switch (C0075) on an R wire.

Stop Lamps
When the brake pedal is pressed, the stop lamp switch contacts close. This allows a feed from fuse 15P of the CJB (C0585) to flow across the switch contacts (C0075) to the following on GP wires:
^ The LH stop lamp (C0121)
^ The RH stop lamp (C0125)
^ The high mounted stop lamp (C0832).

All are provided a ground on B wires.

Hill Descent Control
The stop lamps will also illuminate when HDC is operational. The HDC relay coil is provided an ignition feed from the ignition switch (C0028) on a Y wire. The ground path for the relay coil (C0583) is controlled by the ABS module (C0506) on a YR wire. When energised, the HDC relay (C0585) provides a feed to the stop lamps on GP wires as described previously.

Reverse Lamps

Automatic Transmission
When reverse gear is selected, the Transmission Control Module (TCM) (C0193) sends a message to the instrument cluster (C0230) via the high speed CAN bus on YN (high) and YB (low) wires. The instrument cluster (C0230) acts as a gateway and relays this message to the CJB (C0580) via the medium speed CAN bus on YW (high) and YU (low) wires.

When the CJB registers that reverse gear has been selected, it provides a ground path for the reverse lamp relay coil. The energised relay is now able to provide a feed to fuse 5P, which is also located in the CJB. Fuse 5P (C0585) provides a feed to the LH (C0121) and RH (C0125) reverse lamps on a pair or GN wires. Both lamps are provided a ground on B wires.

Manual Transmission
The transfer box control module (C1855) monitors the condition of the reverse lamp switch (C0675). When reverse gear is selected, the transfer box control module (C1854) sends a message to the instrument cluster (C0230) via the high speed CAN bus on YN (high) and YB (low) wires. The instrument cluster (C0230) acts as a gateway and relays this message to the CJB (C0580) via the medium speed CAN bus on YW (high) and YU (low) wires.

When the CJB registers that reverse gear has been selected, it provides a ground path for the reverse lamp relay coil. The energised relay is now able to provide a feed to fuse 5P, which is also located in the CJB. Fuse 5P (C0585) provides a feed to the LH (C0121) and RH (C0125) reverse lamps on a pair of GN wires. Both lamps are provided a ground on B wires.