Warning Indicators - Part 1
WARNING INDICATORS
The warning indicators are located in various positions in the instrument cluster. The warning indicators can be split into two groups; self controlled and externally controlled.
Self controlled warning indicators are dependent on software logic within the instrument pack for activation. The pack software controls the indicator check illumination at ignition on and all indicators whose operation is controlled by the instrument cluster, the low fuel level warning indicator for example.
Externally controlled indicators are supplied with current from another system controlling module or illuminated by the instrument cluster on receipt of a bus message from another subsystem module. Some indicators are activated by an external subsystem module but the instrument cluster contains the control logic. These indicators are shown in the following table as being both self and externally controlled.
The following table shows the available indicators and indicates if they are subject to an indicator check at ignition on and if they are self or externally controlled.
Warning Indicator Functionality
Warning Indicator Functionality - Part 1:
Warning Indicator Functionality - Part 2:
The functionality for each of the above warning indicators is described below. Some warning indicators are accompanied by a chime from the instrument pack when they are illuminated and also a message in the message center on high line instrument clusters. Some indicators are only available on the low line instrument cluster, with the indicators being replaced with messages on the high line instrument cluster.
1. Air Suspension Indicator
The air suspension indicator is illuminated by the instrument cluster software on receipt of a CAN signal from the air suspension control module. The air suspension control module outputs a number of different signals relating to the air suspension system operation. The instrument cluster interprets the signals and can illuminate the indicator in either an amber or red colour as appropriate. Some signals also include requests for chimes from the instrument cluster to alert the driver.
2. Transfer Box Low Range Indicator
The transfer box low range indicator is illuminated by the instrument cluster software on receipt of CAN signals from the transfer box control module. When a range change from high to low range is in progress, the low range indicator flashes in an green color. When the range change is complete, the low range indicator remains permanently illuminated until high range is selected. The transfer box control module also requests a single chime from the instrument cluster to alert the driver that the requested range change is complete. On high line instrument clusters, the range change information is also displayed in the message center.
3. Hill Descent Control (HDC) Active Indicator
The HDC active indicator is illuminated by the instrument cluster software on receipt of CAN signals from the ABS module. The indicator is illuminated in a green color when HDC is active and the vehicle speed is below a predetermined threshold. If the vehicle speed is faster than the threshold limit, the HDC indicator will flash until the vehicle speed is reduced. On high line instrument clusters a supporting message will also be displayed in the message center.
If the use of HDC causes the brake discs to exceed their pre-determined temperature, the HDC system initiates a 'fade out'. The HDC indicator flashes during 'fade out' and on high line instrument clusters a supporting message is displayed in the message center. When the brake discs have cooled sufficiently, HDC is reactivated and the HDC indicator is permanently illuminated.
4. Dynamic Stability Control (DSC)/Traction Control Indicator
The DSC/traction control indicator is illuminated by the instrument cluster software on receipt of CAN signals from the ABS module. The indicator is illuminated in an amber color for 3 seconds for a bulb check when the ignition is switched on. If no faults exist, the indicator is extinguished after the bulb check period.
When DSC is active, the indicator flashes to inform the driver that the system is regulating engine output and braking forces. If the indicator remains illuminated after the bulb check period or illuminates when driving, the DSC system has a fault or DSC has been deselected by the driver using the DSC switch on the fascia.
5. Ignition/No Charge Indicator
The ignition/no charge indicator is controlled by the instrument cluster software and illuminated by CAN signals from the Engine Control Module (ECM). The indicator illuminates in a red color when the ignition is moved to position II and is extinguished when the engine is started.
If the indicator remains illuminated after the engine has started or illuminates when driving, the alternator charge output has failed.
6. Low Oil Pressure Indicator
The low oil pressure indicator is hardwired directly to the instrument cluster. The indicator is illuminated in a red color when the ignition is moved to position II. When the engine is started and the oil pressure increases the low oil pressure indicator should extinguish. If the indicator remains illuminated or illuminates when driving the vehicle should be stopped at the earliest opportunity and the engine switched off until the fault is rectified.
7. Glow Plugs Active Indicator (Diesel models only)
The glow plugs active indicator is illuminated by the instrument cluster software on receipt of a CAN message from the Engine Control Module (ECM). The indicator is located in the same position as the MIL on petrol models. The indicator illuminates in an amber color when the ignition is moved to position II. The indicator illumination period varies with engine temperature and is some cases will not illuminate when the engine temperature is high. The indicator is controlled by CAN signals from the ECM which equate to the time which the glow plugs are energised to pre-heat the combustion chambers. When the glow plug heating time is complete, the indicator is extinguished indicating to the driver that the engine can now be started.
8. Malfunction Indicator Lamp (MIL)
The MIL is controlled by the instrument cluster software on receipt of CAN signals from the ECM. The indicator is illuminated for a bulb check by the ECM when the ignition is moved to position II. The lamp is extinguished when the engine starts.
If the MIL remains illuminated after the engine is started or illuminates while driving, a fault is present and must investigated at the earliest opportunity. Illumination of the MIL indicates that there is an On-Board Diagnostic (OBD) fault which will cause excessive emissions output. This may relate to either an engine management system fault or a transmission fault.
9. Supplementary Restraint System (SRS) Warning Indicator
The SRS warning indicator is controlled by the restraints control module which transmits CAN signals to the instrument cluster. The warning indicator is illuminated for 6 seconds for a bulb check by the restraints control module when the ignition is moved to position II. If a fault is detected in the SRS the restraints control module illuminates the warning indicator in a red color until the fault is rectified. The instrument cluster also performs a check of the indicator LED functionality. Failure of the indicator LED is transmitted to the driver in the form of an error message which is displayed in the trip meter display.
10 and 11. Left and Right Turn Indicators
The turn indicators are controlled by the instrument cluster software on receipt of CAN signals on the medium speed CAN bus from the Central Junction Box (CJB). When the turn signal indicator switch is operated, the CJB transmits a signal to the instrument cluster to operate the applicable turn indicator. The instrument cluster software controls the flash rate of the indicator which flashes in a green color. During normal turn signal indicator operation the indicator flashes slowly, accompanied simultaneously by a sound from the instrument cluster sounder. If a fault exists, the instrument cluster responds to a fault message from the CJB and flashes the indicator at double speed.
The hazard warning indicators are also controlled by the CJB and the instrument cluster software and operate in the same manner as the turn signal indicators. The hazard warning indicators can operate with the ignition switched off, therefore, the CAN signal from the CJB to the instrument cluster to operate the left and right hand turn signal indicators will also 'wake-up' the instrument cluster.
12. High Beam Indicator
The high beam indicator is controlled by the instrument cluster software on receipt of CAN signals on the medium speed CAN bus from the Central Junction Box (CJB). When the high beam switch is moved to the high beam or headlight flash position, the CJB transmits a CAN message to the instrument cluster to illuminate the high beam indicator in a blue color.