Fuel Consumption Signal

NOTE:
Carry out the following test only if a missing or incorrect fuel consumption signal is determined from the trip computer test.

PROCEDURE:
- Connect VAG 1598 test box to ECM using adapter cable VAG 1598/11. Refer to VAG 1598 Pin Out Box Connecting.
- Connect multimeter (Fluke 83 or equivalent) between Ground and test box socket 31 (fuel consumption signal).
- Start engine and vary engine speed continuously between 1000 RPM and 4000 RPM.
^ Specified value: approx. 0.3-6.0 volts (corresponding to engine speed).

If specified value is obtained but the trip computer does not show a fuel consumption value:
- Stop engine and remove instrument cluster and/or Transmission Control Module (TCM) J217 in succession.

Engine Control Module (ECM) Connectors:

- Using wiring diagram, check for continuity between Engine Control Module (ECM) connector B terminal 11 and:
^ Black 10-pin trip computer connector
^ Transmission Control Module (TCM) J217

If wiring OK:
- Repair instrument cluster malfunction and/or trip computer display unit.

If the specified value is not obtained:
- Stop engine and remove instrument cluster and/or TCM in succession.
- Disconnect black 10-pin harness connector for trip computer and TCM J217 harness connector in succession.
- Start engine and let idle.
^ Specified value: approx. 0.3-0.6 volts.

If specified voltage is not obtained:
- There is a malfunction in trip computer display unit and/or TCM J217 is faulty. See wiring diagrams and/or check TCM.

If the specified voltage is still not obtained:
- Check wiring for short circuit to positive (B+) and/or Ground (GND) between the ECM and trip computer 10-pin harness connector and TCM J217 using wiring diagram.

If there is no short circuit, but the specified values are still not obtained:
- Replace the ECM.