Pinpoint Test B: Incorrect Fuel Gauge Indication - Single Fuel Tank
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test B: Incorrect Fuel Gauge Indication - Single Fuel Tank
Refer to Wiring Diagram Set 60, Instrument Cluster for schematic and connector information. Diagrams By Number
Normal Operation
The fuel level sender (part of the fuel pump module) (gasoline) or the fuel level sensor (diesel) is hardwired to the Instrument Panel Cluster (IPC) between the signal and return circuits. The fuel level sender is a variable resistor that ranges from 10 ohms ± 2 ohms at full (F) and 180 ohms ± 4 ohms at empty (E). The IPC provides a reference voltage to the fuel pump module or fuel level sensor. As the fuel level changes, a float actuates a variable resistor on the fuel pump sender and raises or lowers the fuel level signal voltage depending on the resistance of the fuel level sender. The IPC monitors the changes in voltage and commands the fuel gauge with a corresponding movement of the pointer.
The IPC uses 4 different operating modes to calculate the fuel level:
- Anti-slosh (default mode)
- Key OFF fueling
- Key ON fueling
- Recovery
After a fuel fill up, the time for the fuel gauge to move from empty (E) to full (F) ranges from 2 seconds to 55 minutes depending on which operating mode the fuel gauge is in.
Anti-Slosh Mode
The default fuel gauge mode is called the anti-slosh mode. To prevent fuel gauge changes from fuel slosh (gauge instability due to changes in fuel sender readings caused by fuel moving around in the tank), the fuel gauge takes approximately 55 minutes to go from empty (E) to full (F).
Key OFF Fueling Mode
The key OFF fueling mode (2 seconds to read empty [E] to full [F]) requires 3 conditions be met:
- The key must be in the OFF position when refueling the vehicle.
- At least 15% of the vehicle's fuel capacity must be added to the fuel tank.
- The IPC must receive a valid key ON fuel sender reading within one second of the key being put into the RUN position. The key ON sample readings are considered valid if the fuel sender reading is between 10 ohms ± 2 ohms and 180 ohms ± 4 ohms.
If these conditions are not met, the fuel gauge stays in the default anti-slosh mode, which results in a slow to read full (F) event.
Key ON Fueling Mode
The key ON fueling mode (approximately 60 seconds to read empty [E] to full [F]) requires the following conditions be met:
- Engine speed input greater than 0 rpm.
- The transmission is in PARK (P).
- The key is in the RUN position.
- At least 15% of the vehicle's fuel capacity must be added to the fuel tank.
In key ON fueling mode, a 30-second timer activates after the transmission is put into the PARK (P) position. When the 30-second time has elapsed and at least 15% of the vehicle's fuel capacity has been added, the fuel gauge response time is 60 seconds to read from empty (E) to full (F). When the transmission is shifted out of PARK (P), the fuel gauge strategy reverts to the anti-slosh mode. The key ON fueling mode prevents slow to read full events from happening if the customer refuels the vehicle with the key in the RUN position.
Recovery Mode
Recovery mode is incorporated into the IPC strategy to recover from a missing fuel level input after a refueling event. Missing fuel level inputs result from intermittent opens in the fuel sender or its circuits. Recovery mode (empty [E] to full [F] approximately 20 minutes) is initiated when the following 2 conditions are met:
- The IPC is in the anti-slosh (default) mode.
- The actual fuel level in the tank is greater than what is being displayed by the fuel gauge.
Instrument Panel Cluster (IPC) DTCs
PCM DTCs
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Fuel tank
- Fuel level sensor (diesel only)
- Fuel level sender (float and resistance card)
- Fuel pump module (gasoline only)
- IPC
PINPOINT TEST B: INCORRECT FUEL GAUGE INDICATION - SINGLE FUEL TANK
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 IPC SELF-TEST
- Ignition OFF.
- Check for recorded IPC DTCs from the self-test.
- Are any DTCs recorded?
Yes
For DTC P0460:13, GO to B3. For DTC P0460:11, GO to B7. For all other DTCs, REFER to DTC Charts.
No
GO to B2.
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B2 CARRY OUT THE IPC FUEL GAUGE ACTIVE COMMAND USING THE SCAN TOOL
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IPC DataLogger.
- Select the IPC fuel gauge (FUELLEVEL) active command. Monitor the fuel gauge while scrolling the fuel level at 0%, 50%, and 100%.
- Does the fuel gauge display below E with 0%, half with 50%, and full stop with 100%?
Yes
GO to B10.
No
GO to B14.
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B3 CHECK THE FUEL PUMP MODULE (GASOLINE) OR FUEL LEVEL SENSOR (DIESEL) FOR AN OPEN
- Disconnect: Fuel Pump Module C4033 (Gasoline Narrow Frame Aft-of-Axle Tank).
- Disconnect: Fuel Pump Module C3127 (Gasoline Narrow and Wide Frame Midship Tank).
- Disconnect: Fuel Level Sensor C433 (Diesel Narrow Frame Aft-of-Axle Tank).
- Disconnect: Fuel Level Sensor C3094 (Diesel Wide Frame Midship Tank).
- Connect a fused jumper wire between the fuel pump module (gasoline) or fuel level sensor (diesel) as follows:
- Ignition ON.
- Wait 1 minute.
- Enter the following diagnostic mode on the scan tool: IPC Self-Test.
- NOTE: DTC P0460:13 may also be present when carrying out this test step and should be ignored.
- Clear the IPC DTCs. Repeat the IPC self-test.
- Is DTC P0460:11 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 AND RETURN CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: IPC C220.
- Ignition ON.
- Measure the voltage between the IPC C220-12, circuit VMC11 (YE/VT), harness side and ground; and between the IPC C220-25, circuit RMC32 (GN/BU), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit in question 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 IPC, harness side and the fuel pump module (gasoline) or the fuel level sensor (diesel), harness side as follows:
- Is the resistance less than 5 ohms?
Yes
GO to B6.
No
REPAIR circuit VMC11 (YE/VT) 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 IPC, harness side and the fuel pump module (gasoline) or fuel level sensor (diesel), harness side as follows:
- Is the resistance less than 5 ohms?
Yes
GO to B14.
No
REPAIR circuit RMC32 (GN/BU) for an open. CLEAR the DTCs. REPEAT the self-test.
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B7 CHECK THE FUEL PUMP MODULE (GASOLINE) OR FUEL LEVEL SENSOR (DIESEL) FOR A SHORT TO GROUND
- Disconnect: Fuel Pump Module C4033 (Gasoline Narrow Frame Aft-of-Axle Tank).
- Disconnect: Fuel Pump Module C3127 (Gasoline Narrow and Wide Frame Midship Tank).
- Disconnect: Fuel Level Sensor C433 (Diesel Narrow Frame Aft-of-Axle Tank).
- Disconnect: Fuel Level SensorC3094 (Diesel Wide Frame Midship Tank).
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IPC Self-Test.
- Wait 1 minute.
- NOTE: DTC P0460:11 may also be present when carrying out this test step and should be ignored.
- Clear the IPC DTCs. Repeat the IPC self-test.
- Is DTC P0460:13 retrieved?
Yes
GO to B12.
No
GO to B8.
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B8 CHECK THE FUEL PUMP MODULE (GASOLINE) OR FUEL LEVEL SENSOR (DIESEL) SIGNAL AND RETURN CIRCUITS FOR A SHORT TOGETHER
- Ignition OFF.
- Disconnect: IPC C220.
- Measure the resistance between the IPC C220-12, circuit VMC11 (YE/VT), harness side and the IPC C220-25, circuit RMC32 (GN/BU), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to B9.
No
REPAIR the circuits for a short together. 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 IPC C220-12, circuit VMC11 (YE/VT), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to B14.
No
REPAIR circuit VMC11 (YE/VT) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
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B10 CHECK THE FUEL LEVEL INPUT TO THE IPC
NOTE: Since the IPC may be in anti-slosh fuel indication mode, the PID values may not match the fuel gauge readings. Disregard the actual gauge indication during this test step.
- Ignition OFF.
- Disconnect: Fuel Pump Module C4033 (Gasoline Narrow Frame Aft-of-Axle Tank).
- Disconnect: Fuel Pump Module C3127 (Gasoline Narrow and Wide Frame Midship Tank).
- Disconnect: Fuel Level Sensor C433 (Diesel Narrow Frame Aft-of-Axle Tank).
- Disconnect: Fuel Level Sensor C3094 (Diesel Wide Frame Midship Tank).
- Connect the Instrument Gauge System Tester to the fuel pump module or fuel level sensor as follows:
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IPC DataLogger.
- NOTE: It is extremely important to confirm the gauge tester settings with an ohmmeter to make sure the gauge tester is in the correct position. Failure to follow this check may result in inaccurate test results.
- Monitor the IPC fuel level PID (FUELLEVEL) 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 B14.
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B11 CHECK THE FUEL TANK
- Check the fuel tank for any damage or deformation.
- Is the fuel tank OK?
Yes
For gasoline engines, GO to B12. For diesel engines, INSTALL a new fuel level sensor. REFER to Fuel Tank and Lines - Gasoline and Diesel Fuel Level Sensor. CLEAR the DTCs. REPEAT the self-test.
No
VERIFY the fuel level sensor (diesel) or the fuel pump module (gasoline) are OK. INSTALL a new fuel tank. REFER to Fuel Tank and Lines - Gasoline and Diesel Fuel Tank. CLEAR the DTCs. REPEAT the self-test.
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B12 CHECK THE FUEL PUMP MODULE (GASOLINE) or FUEL LEVEL SENSOR (DIESEL)
NOTE: The fuel pump module (gasoline) and fuel level sensor (diesel) resistance measures between 10 ohms ± 2 ohms at the upper stop position and 180 ohms ± 4 ohms at the lower stop position.
- Remove the fuel pump module (gasoline) or fuel level sensor (diesel). Refer to Fuel Tank and Lines - Gasoline and Diesel Service and Repair.
- Measure the resistance between the fuel pump module (gasoline) or fuel level sensor (diesel) pin 1, component side, and the fuel pump module (gasoline) or fuel level sensor (diesel) pin 2, component side, while moving the float arm from the lower stop position to the upper stop position.
- Does the resistance slowly decrease from approximately 180 ohms to 10 ohms?
Yes
CHECK the fuel pump module (gasoline) or fuel level sensor (diesel) connector for corrosion, damaged or pushed out pins and REPAIR as necessary.
No
For gasoline, GO to B13. For diesel, INSTALL a new fuel level sensor. CLEAR the DTCs. REPEAT the self-test.
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B13 CHECK THE FUEL LEVEL SENDER
NOTE: The fuel level sender resistance measures between 10 ohms ± 2 ohms at the upper stop position and 180 ohms ± 4 ohms at the lower stop position.
- Disconnect the fuel level sender input wire from the fuel pump module.
- Measure the resistance between the fuel level sender connector pin 1, harness side and the fuel level sender connector pin 2, harness side while slowly moving the float arm between the lower and upper stop position.
- Does the resistance slowly decrease from approximately 180 ohms to 10 ohms?
Yes
INSTALL a new fuel pump module. REFER to Fuel Tank and Lines - Gasoline and Diesel Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
INSTALL a new fuel level sender (float and card). CLEAR the DTCs. REPEAT the self-test.
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B14 CHECK FOR CORRECT IPC OPERATION
- Disconnect the IPC connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IPC connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). 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.
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