Consumption signal, checking
NOTE:
- In the Audi A8 GP, the consumption signal is transmitted from the Engine Control Module (ECM) to the instrument cluster via the power train data-bus.
- Malfunctions between the Engine Control Module (ECM) and the instrument cluster an only be recognized via On Board Diagnostic (OBD) of the instrument cluster. See INSTRUMENT CLUSTER, ON BOARD DIAGNOSTIC (OBD) .
Test sequence:
- Start engine and perform a road test.
- Observe the consumption signal in the instrument cluster.
What appears in consumption display?
- always 0.0 L/100 km or always 51 L/100 km.
- Check DTC memory in instrument cluster to determine whether there are malfunctions in the power train data-bus affecting the communication between the Engine Control Module (ECM) and the consumption display in the instrument cluster. See CHECK DTC MEMORY (FUNCTION 02) .
- If there is no malfunction in the power train data-bus, and no communication with the Engine Control Module (ECM), check control modules that are connected to the power train data-bus for malfunctions. See IF YOU CANNOT DETERMINE A CAUSE FOR THE MALFUNCTION, E.G. "POWER TRAIN DATA-BUS FAULTY", CHECK WHETHER ONE OF THE CONTROL MODULES MAY BE RESPONSIBLE FOR THE DTC .
- If no malfunctions are found, remove instrument cluster. See Instrument cluster, removing and installing .
- Consumption display has an unreasonable or erratic indication. See if consumption display deviates from actual consumption.
- Adapt consumption display. See ADAPTATION OF FUEL GAUGE .