Pinpoint Test B: Incorrect Fuel Gauge Indication - Single Sender L-Shaped Fuel Tank
Instrumentation, Message Center and Warning Chimes
Pinpoint Test B: Incorrect Fuel Gauge Indication - Single Sender L-Shaped Fuel Tank
Refer to Wiring Diagram Set 60 (Fusion/Milan/MKZ, Fusion Hybrid, Milan Hybrid, MKZ Hybrid), Instrument Cluster for schematic and connector information. Diagrams By Number
Normal Operation
The fuel pump module is hardwired to the Instrument Panel Cluster (IPC) between the signal circuit and the signal return circuit, which is grounded internally within the IPC. The fuel level sender (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 IPC provides a reference voltage to the fuel pump module on the signal circuit. As the fuel level changes, a float actuates a variable resistor on the fuel level sender (float and card), raising or lowering 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.
On flex-fuel vehicles, basic fuel level indication is the same as gasoline vehicles, except that the flex-fuel vehicles require a DC-AC interface (internal to the IPC), used to prevent chemical reactions created by the interaction of A/C current with the fuel.
The IPC uses 4 different operating modes to calculate the fuel level:
- Anti-slosh (default mode)
- Ignition OFF fueling
- Ignition 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 sensor 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 ignition OFF fueling mode (2 seconds to read empty [E] to full [F]) requires 3 conditions be met:
- The ignition must be in the OFF mode 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 ignition ON fuel sensor reading within one second of the ignition being put into the RUN mode. The key ON sample readings are considered valid if the fuel sensor reading is between 10 ohms ± 2 ohms and 180 ohms ± 4 ohms.
If these conditions are not met, the fuel gauge stays in the anti-slosh mode, which results in a slow to read full (F) event.
Key ON Fueling Mode
The ignition ON fueling mode (approximately 60 seconds to read empty [E] to full [F]) requires the following conditions be met:
- Engine speed greater than 0 rpm.
- The transaxle is in PARK (P) or NEUTRAL (N).
- The ignition is in the RUN mode.
- At least 15% of the vehicle's fuel capacity must be added to the fuel tank.
In ignition ON fueling mode, a 30-second timer activates after the transaxle is put into the PARK (P) or NEUTRAL (N) 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 transaxle is shifted out of PARK (P) or NEUTRAL (N), the fuel gauge strategy reverts to the anti-slosh mode. The ignition ON fueling mode prevents slow to read full events from happening if the customer refuels the vehicle with the ignition in the RUN mode.
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 sensor 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 pump module
- Fuel level sender (float and card)
- Fuel tank
- IPC
PINPOINT TEST B: INCORRECT FUEL GAUGE INDICATION - SINGLE SENDER L-SHAPED FUEL TANK
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Following any fuel gauge repairs, remove fuse 26 (10A) for one minute then reinstall to reset the fuel gauge timers.
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B1 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST
- Check for recorded DTCs from the IPC 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. Instrumentation, Message Center and Warning Chimes
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 .
- NOTE: Make sure to set the scan tool to empty or 0% before beginning this test.
- Select the IPC fuel gauge (FUELLEVEL) active command. Command the fuel gauge from 0% to 25%, 50%, 75% and 100% while observing the fuel gauge.
- Does the fuel gauge begin at E (empty), move to approximately 1/8-1/4, just under 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 RMC32 (GN/BU), harness side and the fuel pump module C433-2, circuit VMC11 (YE/VT), harness side.
- Ignition ON.
- Wait one 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 step and should be ignored at this time.
- Repeat the IPC self-test.
- Retrieve the IPC continuous DTCs.
- 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 CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: IPC C220 .
- Ignition ON.
- For non-hybrid, measure the voltage between the IPC C220-15, circuit VMC11 (YE/VT), harness side and ground; and between the IPC C220-2, circuit RMC32 (GN/BU), harness side and ground.
- For hybrid, measure the voltage between the IPC C220-25, circuit VMC11 (YE/VT), harness side and ground; and between the IPC C220-12, circuit RMC32 (GN/BU), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit in question. 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.
- For non-hybrid, measure the resistance between the IPC C220-15, circuit VMC11 (YE/VT), harness side and the fuel pump module assembly C433-2, circuit VMC11 (YE/VT), harness side.
- For hybrid, measure the resistance between the IPC C220-25, circuit VMC11 (YE/VT), harness side and the fuel pump module assembly C433-2, circuit VMC11 (YE/VT), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to B6.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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B6 CHECK THE FUEL LEVEL RETURN CIRCUIT FOR AN OPEN
- For non-hybrid, measure the resistance between the IPC C220-2, circuit RMC32 (GN/BU), harness side and the fuel pump module assembly C433-1, circuit RMC32 (GN/BU), harness side.
- For hybrid, measure the resistance between the IPC C220-12, circuit RMC32 (GN/BU), harness side and the fuel pump module assembly C433-1, circuit RMC32 (GN/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to B13.
No
REPAIR the circuit. 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: IPC Self-Test .
- NOTE: DTC P0460:11 may also be present when carrying out this step and should be ignored at this time.
- Repeat the IPC self-test.
- Retrieve the IPC continuous DTCs.
- Is DTC P0640:13 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
- Ignition OFF.
- Disconnect: IPC C220 .
- On non-hybrid, measure the resistance between the IPC C220-15, circuit VMC11 (YE/VT), harness side and the IPC C220-2, circuit RMC32 (GN/BU), harness side.
- On hybrid, measure the resistance between the IPC C220-25, circuit VMC11 (YE/VT), harness side and the IPC C220-12, circuit RMC32 (GN/BU), 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
- For non-hybrid, measure the resistance between the IPC C220-15, circuit VMC11 (YE/VT), harness side and ground.
- For hybrid, measure the resistance between the IPC C220-25, circuit VMC11 (YE/VT), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to B13.
No
REPAIR the circuit. 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 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 VMC11 (YE/VT), harness side and the other lead to the fuel pump module assembly C433-1, circuit RMC32 (GN/BU), harness side.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IPC PIDs .
- 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 IPC fuel level (FLI) 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 Removal and Replacement.
CLEAR the DTCs. REPEAT the self-test.
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B12 CHECK THE FUEL LEVEL SENDER (FLOAT AND CARD)
NOTE: The fuel level sender (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 Service and Repair.
- NOTE: Disconnect the fuel level sender (float and card) input wire from the fuel pump module for this measurement.
- Measure the resistance between the fuel level sender (float and card) input wire and the fuel level sender (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 Service and Repair.
CLEAR the DTCs. REPEAT the self-test.
No
INSTALL a new fuel level sender (float and card). REFER to Fuel Tank and Lines Service and Repair.
CLEAR the DTCs. REPEAT the self-test.
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B13 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. CLEAR the DTCs. REPEAT the self-test.
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