Pinpoint Test B: Incorrect Fuel Gauge Indication
Instrumentation and Warning Chimes
Pinpoint Tests
Pinpoint Test B: Incorrect Fuel Gauge Indication
Refer to Wiring Diagram Set 60, Instrument Cluster for schematic and connector information. Diagrams By Number
Normal Operation
The fuel pump module is hardwired to the Instrument Cluster (IC) between the fuel level signal circuit and the fuel level signal return circuit. The fuel level sensor (float and card) is a variable resistor attached to the fuel pump module that ranges from 180 ohms± 4 ohms at empty (E) and 10 ohms± 2 ohms at full (F). The IC provides a reference voltage to the fuel pump module on the fuel level input circuit. As the fuel level changes, a float actuates a variable resistor on the fuel level sensor card and raises or lowers the fuel level signal voltage depending on the resistance of the fuel level sensor. The IC monitors the changes in voltage and commands the fuel gauge with a corresponding movement of the pointer. If the IC detects a fault on the fuel level input circuit, fuel level return circuit or the fuel pump module, the IC defaults the fuel gauge to the empty (E) position and turns on the low fuel warning indicator.
IC DTCs
PCM DTCs
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Fuel pump module
- Fuel level sensor (card and float)
- Fuel tank
- IC
PINPOINT TEST B: INCORRECT FUEL GAUGE INDICATION
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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B1 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST
- Check for recorded IC DTCs from the self-test.
- Are any DTCs recorded?
Yes
For DTC B1202, GO to B3.
For DTC B1204, GO to B7.
For all other DTCs, REFER to DTC Charts. Diagnostic Trouble Code Tests and Associated Procedures
No
GO to B2.
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B2 CARRY OUT THE IC FUEL GAUGE ACTIVE COMMAND USING THE SCAN TOOL
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- Select the IC fuel gauge (FUEL_GAUGE) active command. Command the fuel gauge from 0% to 20%, 50%, 70% and 100% while observing the fuel gauge.
- Does the fuel gauge begin at (E) empty, move to approximately 1/4, 1/2, 3/4 and F (full)?
Yes
GO to B10.
No
GO to B13.
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B3 CHECK THE FUEL PUMP MODULE FOR AN OPEN
- Ignition OFF.
- Disconnect: Fuel Pump Module C433.
- Connect a fused jumper wire between the fuel pump module C433-1, circuit 8-GA7 (WH/RD), harness side and the fuel pump module C433-2, circuit 9-GA7 (BN/RD), harness side.
- Ignition ON.
- Wait one minute.
- Enter the following diagnostic mode on the scan tool: IC Self-Test.
- NOTE: DTC B1202 may also be present when carrying out this step and should be ignored at this time.
- Repeat the IC self-test.
- Retrieve the IC continuous DTCs.
- Is DTC B1204 retrieved?
Yes
REMOVE the jumper wire. GO to B12.
No
REMOVE the jumper wire. GO to B4.
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B4 CHECK THE FUEL LEVEL SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: IC C220b.
- Ignition ON.
- Measure the voltage between the IC C220b-14, circuit 9-GA7 (BN/RD), harness side and ground.
- Is any voltage present?
Yes
REPAIR circuit 9-GA7 (BN/RD) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to B5.
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B5 CHECK THE FUEL LEVEL SIGNAL CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between the IC C220b-14, circuit 9-GA7 (BN/RD), harness side and the fuel pump module assembly C433-2, circuit 9-GA7 (BN/RD), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to B6.
No
REPAIR circuit 9-GA7 (BN/RD) for an open. CLEAR the DTCs. REPEAT the self-test.
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B6 CHECK THE FUEL LEVEL RETURN CIRCUIT FOR AN OPEN
- Measure the resistance between the IC C220b-15, circuit 8-GA7 (WH/RD), harness side and the fuel pump module assembly C433-1, circuit 8-GA7 (WH/RD), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to B13.
No
REPAIR circuit 9-GA7 (BN/RD) for an open. CLEAR the DTCs. REPEAT the self-test.
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B7 CHECK THE FUEL PUMP MODULE FOR A SHORT TO GROUND
- Disconnect: Fuel Pump Module C433.
- Ignition ON.
- Wait one minute.
- Enter the following diagnostic mode on the scan tool: IC Self-Test.
- NOTE: DTC B1204 may also be present when carrying out this step and should be ignored at this time.
- Repeat the IC self-test.
- Retrieve the IC continuous DTCs.
- Is DTC B1202 retrieved?
Yes
GO to B12.
No
GO to B8.
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B8 CHECK THE FUEL LEVEL SIGNAL AND RETURN CIRCUITS FOR A SHORT TOGETHER
- Disconnect: IC C220b.
- Ignition OFF.
- Measure the resistance between the IC C220b-14, circuit 9-GA7 (BN/RD), harness side and the IC C220b-15, circuit 8-GA7 (WH/RD), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to B9.
No
REPAIR the circuits. CLEAR the DTCs. REPEAT the self-test.
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B9 CHECK THE FUEL LEVEL SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between the IC C220b-14, circuit 9-GA7 (BN/RD), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to B13.
No
REPAIR circuit 9-GA7 (BN/RD) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
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B10 CHECK THE FUEL LEVEL INPUT TO THE IC
NOTE: Since the IC may be in anti-slosh fuel indication mode, the self-test and tester values may not match the fuel gauge readings. The actual gauge indication should be disregarded during this test step.
- Ignition OFF.
- Disconnect: Fuel Pump Module Assembly C433.
- Connect one lead of the instrument gauge system tester to the fuel pump module assembly C433-2, circuit 9-GA7 (BN/RD), harness side and the other lead to the fuel pump module assembly C433-1, circuit 8-GA7 (WH/RD), harness side.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- NOTE: It is extremely important to confirm the gauge tester settings with an ohmmeter to make sure that the gauge tester is in the correct position. Failure to follow this check may result in inaccurate test results.
- Monitor the IC fuel level (FUELLVL1) PID with the gauge tester set at 180 ohms, 90 ohms, 55 ohms, 30 ohms and 10 ohms.
- Does the PID begin at approximately 0%, move to 25%, 50%, 75% then 100%?
Yes
DISCONNECT the instrument gauge system tester. GO to B11.
No
DISCONNECT the instrument gauge system tester. GO to B13.
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B11 CHECK THE FUEL TANK
- Check the fuel tank for any damage or deformation.
- Is the fuel tank OK?
Yes
GO to B12.
No
VERIFY the fuel level sensor and fuel pump module are OK. INSTALL a new fuel tank. REFER to Fuel Tank and Lines Fuel Tank. TEST the system for normal operation.
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B12 CHECK THE FUEL LEVEL SENSOR (FLOAT AND CARD)
NOTE: The fuel level sensor (float and card) resistance measures between 180 ohms± 4 ohms at the lower stop position and 10 ohms± 2 ohms at the upper stop position.
- Remove the fuel pump module. Refer to Fuel Tank and Lines Fuel Pump Module.
- NOTE: Disconnect the fuel level sensor (float and card) input wire from the fuel pump module for this measurement.
- Measure the resistance between the fuel level sensor (float and card) input wire and the fuel level sensor (float and card) ground while slowly moving the float arm between the lower and upper stop position.
- Does the resistance slowly decrease from approximately 180 ohms at the lower stop to 10 ohms at the upper stop?
Yes
INSTALL a new fuel pump module. REFER to Fuel Tank and Lines Fuel Pump Module. CLEAR the DTCs. REPEAT the self-test.
No
INSTALL a new fuel level sensor (float and card). REFER to Fuel Tank and Lines Fuel Level Sender. CLEAR the DTCs. REPEAT the self-test.
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B13 CHECK FOR CORRECT IC OPERATION
- Disconnect the IC connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IC connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new IC. REFER to Instrument Cluster (IC) Service and Repair. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.
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