Fuel Level Signal, Checking

NOTES:
- 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.
- 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.

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 -0- 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.