Test B: Incorrect Fuel Gauge Indication

PINPOINT TEST B: INCORRECT FUEL GAUGE INDICATION

B1-B4:

B4-B7:

B7-B9:

B10-B12:

Normal Operation
The fuel level status is monitored by the rear electronic module (REM) from the fuel delivery module through circuit 8-GA7 (WH/RD) and the jet pump module through circuit 8-GA25 (WH/BU). The REM sends the fuel level data to the instrument cluster over the communication network. The REM provides a signal return (ground) through circuit 9-GA1 (BN/RD), which is spliced to the fuel delivery module return circuit 9-GA7 (BN/RD), and the jet pump module return circuit 9-GA25 (BN/BU).

The normal operating range of the fuel delivery module sender is from 16 ± 2 ohms at empty (E) to 155 ± 4 ohms at full (F). The normal operating range of the jet pump module is from 19 ± 2 ohms at empty (E) to 160 ± 2 ohms at full (F). Instrument cluster DTC B1202 is set if circuit 8-GA7 (WH/RD) is open or shorted to voltage. Instrument cluster DTC B1204 is set if circuit 8-GA7 (WH/RD) is shorted to ground. Instrument cluster DTC B2627 is set if circuit 8-GA25 (WH/BU) is open. Instrument cluster DTC B2628 is set if circuit 8-GA25 (WH/BU) is shorted to ground. REM DTC B1201 is set if either the fuel delivery module or the jet pump module are out of range or if the data reading is invalid.

If the jet pump module is open, the fuel gauge defaults to the fuel delivery module value only and the fuel gauge indicates E to 1/2 tank (depending on the fuel level on the fuel pump delivery module side of the tank). If the fuel delivery module is open, the fuel gauge defaults to the empty position. Instrument cluster DTC B2879 is set if the fuel level measured by the jet pump module is greater than the fuel level measured by the fuel delivery module.

Possible Causes
- circuit 8-GA7 (WH/RD) open, short to ground, or short to voltage
- circuit 8-GA25 (WH/BU) open, short to ground, or short to voltage
- circuit 9-GA1 (BN/RD) open, short to ground, or short to voltage
- circuit 9-GA7 (BN/RD) open, short to ground, or short to voltage
- circuit 9-GA25 (BN/BU) open, short to ground, or short to voltage
- fuel delivery module
- jet pump module
- fuel tank
- REM
- instrument cluster