Test B: Incorrect Fuel Gauge Indication

PINPOINT TEST B: INCORRECT FUEL GAUGE INDICATION

B1-B2:

B2-B4:

B4-B5:

B5-B7:

Normal Operation
The fuel level is determined using a variable resistance fuel sender unit, with an approximate resistance range between 15 ohms at empty (E) and 160 ohms at full (F) ± 1%. If the vehicle is equipped with 1 fuel tank, the fuel pump sender is hardwired to the instrument cluster through the signal circuit 29 (YE/WH) and the return circuit 396 (BK/OG). If the vehicle is equipped with an auxiliary fuel tank, the primary fuel pump sender is hardwired to the instrument cluster through the signal circuit 675 (YE/LB) and the return circuit 396 (BK/OG), and the secondary fuel pump sender is hardwired to the instrument cluster through the signal circuit 29 (YE/WH) and the return circuit 396 (BK/OG). The instrument cluster monitors the resistance readings sent to the instrument cluster from the fuel senders and commands the fuel gauge with a corresponding movement of the pointer.

Possible Causes
- circuit 29 (YE/WH) open, short to ground or short to voltage
- circuit 396 (BK/OG) open or short to ground
- circuit 675 (YE/LB) open, short to ground or short to voltage
- fuel tank
- fuel pump module
- instrument cluster