Fuel Gauge: Testing and Inspection

Tools required:
- Instrument tester VW 1301
- Digital multimeter Fluke 83 (US 1119)
- Connector test kit V.A.G 1594/A
- Applicable wiring diagram
- Repair Manual Engine, Repair Group 20, Fuel Supply
- Approved fuel storage cant, such as Tempo Products FM 3000 or equivalent


CAUTION: DO NOT damage, enlarge or bend connector terminals or cavities by forcing probes into them when performing electrical checks. Use connector test kit VW 1594 to make the necessary electrical connections.


WARNING:
When working on open fuel system:
Fire hazard and danger of explosion! Do not smoke. Keep away anything that can ignite fuel or fuel fumes.

- Before removing or installing fuel level sensor, the suction pipe of a workshop exhaust system must be located near the fuel tank opening to immediately suck gas vapors away. If no exhaust system is available use a radial fan (motor must be located outside the air flow) with a volume of at least 15 m(3)/hr (9 cfm).
- Wear fuel resistant gloves whenever working on open fuel system.


NOTE:
- If the wiring to the Fuel Level Sensor (G) has an open or short circuit, the gauge needle will remain on the left side of the scale.
- Ensure ignition is switched off when filling fuel tank, otherwise the correct fuel level indication will only be present after a long delay
- The fuel gauge needle will only move when more that 4 liters (one gallon) are in the tank Less fuel will not affect the needle.
- In the event that the fuel tank was filled completely with the ignition switched on (full fuel level indication after a long delay), the gauge can be corrected by disconnecting and reconnecting the battery ground (GND) strap or accessing the Instrument Cluster DTC.


Test conditions:
- Fuses S 16 and S 21 on fuse/relay panel OK







Test values
60 Fuel gauge needle points to scale line for full = 1/1
160 Fuel gauge needle points to scale line for half full = 1/2
358 Fuel gauge needle points to area of scale field for reserve
546 Fuel gauge needle points to area of scale field for empty

Permissible deviation: One needle width.
If you get these values, check fuel gauge sender (G)

Troubleshooting: