Warning Lamps

Warning Lamps

The warning lamps operate as follows:

Illumination of the low fuel warning lamp (C0233) is controlled internally within the instrument pack by the speedometer. For more information, refer to the Fuel Gauge section earlier. Illumination of the differential lock warning lamp (C0233) is controlled by differential lock unit (C0306) on a BU wire. When differential lock is selected, the switch contacts within the unit close creating a path to earth (C0307) on a B wire. Current from fuse 15 of the passenger compartment fuse box (C0580) is now able to flow across the bulb. Illumination of the oil pressure warning lamp (C0233) is controlled by the oil pressure switch (C0187) on a WN wire. When low oil pressure is detected by the switch, the switch contacts close creating a path to earth. Current from fuse 15 of the passenger compartment fuse box (C0580) is now able to flow across the bulb. Illumination of the ignition/no charge warning lamp (C0233) is controlled by the alternator (C0236 on Td5 vehicles, C0185 on 300 Tdi vehicles) on an NY wire. When the alternator is not producing an output voltage, current is able to flow across the bulb to earth via the alternator. When the alternator outputs a voltage equal to that supplied by fuse 15 of the passenger compartment fuse box (C0580), the lamp will extinguish as the potential difference across the lamp is 0 volts. Illumination of the transmission oil warning lamp (C0230) is controlled by the transmission oil temperature switch (C0686) on an SR wire. When transmission oil temperature exceeds the recommended limits, the switch contacts close creating a path to earth (C0687) on a B wire. Current from fuse 15 of the passenger compartment fuse box (C0580) is now able to flow across the bulb. Illumination of the ABS warning lamp is controlled by the ABS ECU. If the ABS ECU (C0504) detects a fault in the system, it provides a feed to the ABS warning lamp (C0230) on an RS wire. This triggers a series of transistors and diodes within the instrument pack to allow current from fuse 15 of the passenger compartment fuse box (C0580) to flow across the bulb. The bulb is earthed via the instrument pack on a B wire.

NOTE: If ABS isn't fitted, a shorting link is fitted to the instrument pack between C0234–6 and C0234–10. This link prevents the ABS warning lamp illuminating.