Fuel Level Signal: Testing and Inspection

NOTE:
- If the fuel level in the tank is too low (less than 3.2 gal); combustion misfire, oxygen sensor and fuel system malfunctions could occur. In these cases the malfunction "Fuel tank level too low" is stored in DTC memory.
- The fuel tank level signal is monitored by the Engine Control Module (ECM).


Checking requirements:
- Control Module coding OK, Refer to "Code Control Module". Code Control Module (Function 07)
- Fuel content greater than 3.2 gal (12 liters).
- Instrument cluster fuel gauge OK.
- Switch ignition ON.
- Using VAG 1551 scan tool, select "Read Measuring Value Block" function 08, display group 027, display field 2, refer to "Read Measuring Value Block (Function 08)". Read Measuring Value Block (Function 08)

Indicated on display; note display field 2


Read measuring value block 27 ->
1 2 3 4


Specified value: 0

- Start engine and let idle.
Specified value: 1
- Press -> button.
- Select "End Output" function 06.
- Press -Q- button to confirm input.

If the specified value is not obtained, even though coding is OK:
- Connect VAG 1598/19 test box to ECM harness connector.
- Check wiring for open or short circuit between ECM and instrument cluster, using wiring diagram.