PINPOINT TEST B: INCORRECT FUEL GAUGE INDICATION

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1 2012 Ford Truck Flex AWD V6-3.5L Vehicle > Instrument Panel, Gauges and Warning Indicators > Testing and Inspection > Pinpoint Tests > Instrumentation, Message Center and Warning Chimes PINPOINT TEST B: INCORRECT FUEL GAUGE INDICATION Instrumentation, Message Center 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. See: Vehicle > Electrical rmal Operation The fuel tank is a saddle tank design with variable resistance senders, driven by floats, that provide resistances related to the fuel level in each side to the Instrument Cluster (IC). The fuel level is determined using variable resistance fuel sender units, with an approximate resistance range between 180 ohms ± 4 ohms at empty (E) and 10 ohms ± 2 ohms at full (F). The IC (Instrument Cluster) sends a reference voltage to the fuel pump module (RH side) and the fuel level sensor (LH side). As the fuel level changes, a float actuates a variable resistor on the fuel pump module and fuel level sensor, raising or lowering the fuel level signal voltage depending on the resistance of the fuel level sender (float and card). The IC (Instrument Cluster) monitors the changes in voltage from both senders and commands the fuel gauge with a corresponding movement of the pointer. If the IC (Instrument Cluster) detects the fuel level sensor circuitry is open, the fuel gauge defaults to the fuel pump module value only and the fuel gauge indicates E to one-half tank. If the IC (Instrument Cluster) detects fuel pump module circuitry is open, the fuel gauge defaults to the empty position. The IC (Instrument Cluster) 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 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). 1/20

2 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 mode when refueling the vehicle. - At least 15% of the vehicle's fuel capacity must be added to the fuel tank. - The IC (Instrument Cluster) must receive a valid key 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 key ON fueling mode (approximately 90 seconds to read empty [E] to full [F]) requires the following conditions be met: - The transaxle is in PARK (P) - The key is in the RUN mode. - 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 transaxle 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 90 seconds to read from empty (E) to full (F). When the transaxle 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 mode. Recovery Mode Recovery mode is incorporated into the IC (Instrument Cluster) 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 IC (Instrument Cluster) 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 Cluster (IC) DTCs 2/20

3 PCM DTCs 3/20

4 This pinpoint test is intended to diagnose the following: - Wiring, terminals or connectors - Fuel tank transfer tube - Fuel pump module - Fuel level sensor - Fuel level sender (float and card) - Fuel lines - Fuel tank - IC (Instrument Cluster) 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. 4/20

5 B1 RETRIEVE THE RECORDED DTCs FROM THE IC (Instrument Cluster) SELF-TEST - Ignition OFF. - Check for recorded IC (Instrument Cluster) DTCs from the self-test. Are any DTCs recorded? For DTC B1204 or DTC B2628, GO to B2. For DTC B1202, GO to B6. For DTC B2627, GO to B10. For DTC B2879, GO to B15. GO to B14. B2 CHECK THE FUEL SENDER FOR A SHORT TO GROUND - Disconnect: Fuel Pump Module C3127(DTC B1204) or Fuel Level Sensor C3270(DTC B2628). - Ignition ON. - Wait one minute. - Enter the following diagnostic mode on the scan tool:ic (Instrument Cluster) Self-Test. - NOTE: DTC B1204 or DTC B2628 may also be present. Repeat the IC (Instrument Cluster) self-test. Is DTC B1202 or DTC B2627 retrieved? GO to B17. GO to B3. 5/20

6 B3 CHECK THE FUEL LEVEL SIGNAL CIRCUITS FOR A SHORT TO GROUND - Ignition OFF. - Disconnect:IC (Instrument Cluster) C Measure the resistance between the IC (Instrument Cluster) C220-15(DTC B1204), circuit VMC11 (YE/VT) harness side and ground; or between the IC (Instrument Cluster) C220-14(DTC B2628), circuit VMC23 (GN/OG) harness side and ground. Is the resistance greater than 10,000 ohms? For DTC B1204, GO to B4. For DTC B2628, GO to B5. REPAIR the circuit in question for a short to ground. CLEAR the DTCs. REPEAT the self-test. B4 CHECK THE FUEL PUMP MODULE SIGNAL AND RETURN CIRCUITS FOR A SHORT TOGETHER - Measure the resistance between the IC (Instrument Cluster) C220-15, circuit VMC11 (YE/VT), harness side and between the IC (Instrument Cluster) C220-2, circuit RMC32 (GN/BU), harness side. 6/20

7 Is the resistance greater than 10,000 ohms? GO to B22. REPAIR the circuit in question for a short together. CLEAR the DTCs. REPEAT the self-test. B5 CHECK THE FUEL LEVEL SENSOR SIGNAL AND RETURN CIRCUITS FOR A SHORT TOGETHER - Measure the resistance between the IC (Instrument Cluster) C220-14, circuit VMC23 (GN/OG), harness side and the IC (Instrument Cluster) C220-1, circuit RMC33 (WH/VT), harness side. Is the resistance greater than 10,000 ohms? 7/20

8 GO to B22. REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test. B6 CHECK THE FUEL PUMP MODULE CIRCUITRY FOR AN OPEN - Ignition OFF. - Disconnect: Fuel Pump Module C Connect a fused jumper wire between the fuel pump module C3127-2, circuit VMC11 (YE/VT), harness side and the fuel pump module C3127-1, circuit RMC32 (GN/BU), harness side. - Ignition ON. - Wait one minute. - Enter the following diagnostic mode on the scan tool:ic (Instrument Cluster) Self-Test. - NOTE: DTC B1202 may also be present when carrying out this step and should be ignored. Repeat the IC (Instrument Cluster) self-test. - Retrieve the IC (Instrument Cluster) continuous DTCs. Is DTC B1204 retrieved? 8/20

9 REMOVE the jumper wire. GO to B17. REMOVE the jumper wire. GO to B7. B7 CHECK THE FUEL PUMP MODULE CIRCUIT FOR A SHORT TO VOLTAGE - Disconnect:IC (Instrument Cluster) C Ignition ON. - Measure the voltage between the IC (Instrument Cluster) C220-15, circuit VMC11 (YE/VT), harness side and ground; and between the IC (Instrument Cluster) C220-2, circuit RMC32 (GN/BU), harness side and ground. Is any voltage present? REPAIR the circuit in question for a short to voltage. CLEAR the DTCs. REPEAT the self-test. GO to B8. B8 CHECK THE FUEL PUMP MODULE SIGNAL CIRCUIT FOR AN OPEN - Measure the resistance between the IC (Instrument Cluster) C220-15, circuit VMC11 (YE/VT), harness side and the fuel pump module C3127-2, circuit 9/20

10 VMC11 (YE/VT), harness side. Is the resistance less than 5 ohms? GO to B9. REPAIR circuit VMC11 (YE/VT). CLEAR the DTCs. REPEAT the self-test. B9 CHECK THE FUEL LEVEL RETURN CIRCUIT FOR AN OPEN - Measure the resistance between the IPC (Instrument Panel Cluster) C220-2, circuit RMC32 (GN/BU), harness side and the fuel pump module C3127-1, circuit RMC32 (GN/BU), harness side. 10/20

11 Is the resistance less than 5 ohms? GO to B22. REPAIR circuit RMC32 (GN/BU). CLEAR the DTCs. REPEAT the self-test. B10 CHECK THE FUEL LEVEL SENSOR CIRCUITRY FOR AN OPEN - Connect a fused jumper wire between the fuel level sensor C3270-2, circuit VMC23 (GN/OG), harness side and the fuel level sensor C3270-1, circuit RMC33 (WH/VT), harness side. - Ignition ON. - Wait one minute. - Enter the following diagnostic mode on the scan tool:ic (Instrument Cluster) Self-Test. - NOTE: DTC B2627 may also be present when carrying out this step and should be ignored. Repeat the IC (Instrument Cluster) self-test. - Retrieve the IC (Instrument Cluster) continuous DTCs. Is DTC B2628 retrieved? 11/20

12 REMOVE the jumper wire. GO to B17. REMOVE the jumper wire. GO to B11. B11 CHECK THE FUEL LEVEL SENSOR CIRCUIT FOR A SHORT TO VOLTAGE - Disconnect:IC (Instrument Cluster) C Ignition ON. - Measure the voltage between the IC (Instrument Cluster) C220-14, circuit VMC23 (GN/OG), harness side and ground; and between the IC (Instrument Cluster) C220-1, circuit RMC33 (WH/VT), harness side and ground. Is any voltage present? REPAIR the circuit in question for a short to voltage. CLEAR the DTCs. REPEAT the self-test. GO to B12. B12 CHECK THE FUEL LEVEL SENSOR SIGNAL CIRCUIT FOR AN OPEN - Measure the resistance between the IC (Instrument Cluster) C220-14, circuit VMC23 (GN/OG), harness side and the fuel level sensor C3270-2, circuit VMC23 (GN/OG), harness side. 12/20

13 Is the resistance less than 5 ohms? GO to B13. REPAIR circuit VMC23 (GN/OG). CLEAR the DTCs. REPEAT the self-test. B13 CHECK THE FUEL LEVEL SENSOR RETURN CIRCUIT FOR AN OPEN - Measure the resistance between the IPC (Instrument Panel Cluster) C220-1, circuit RMC33 (WH/VT), harness side and the fuel level sensor C3270-1, circuit RMC33 (WH/VT), harness side. Is the resistance less than 5 ohms? 13/20

14 GO to B22. REPAIR the circuit RMC33 (WH/VT) for an open. CLEAR the DTCs. REPEAT the self-test. B14 CARRY OUT THE IC (Instrument Cluster) FUEL GAUGE ACTIVE COMMAND USING THE SCAN TOOL - Ignition ON. - Enter the following diagnostic mode on the scan tool:ic (Instrument Cluster) DataLogger. - NOTE: Make sure to set the scan tool to 0 or full empty (E) before beginning this step. Select the IC (Instrument Cluster) fuel gauge (FUEL) 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 1/4, 1/2, 3/4 and F (full)? GO to B15. GO to B22. B15 INSPECT THE FUEL TANK - Visually inspect the fuel tank for any damage or deformation. Is the fuel tank OK? GO to B16. INSTALL a new fuel tank. REFER to Section CLEAR the DTCs. REPEAT the self test. B16 INSPECT THE FUEL TANK TRANSFER TUBE CONNECTIONS 14/20

15 NOTE: DTC B2879 indicates a fuel transfer concern with the fuel transfer tube or the jet pump (part of the fuel pump module). - Remove the fuel pump module and the fuel level sensor. Refer to Section Inspect the fuel tank transfer tube, connections, the fuel pump module and the fuel level sensor for any damage or deformation. Are the fuel tank transfer tube, connections, the fuel pump module and the fuel level sensor OK? For DTC B2879, INSTALL a new fuel pump module. REFER to Section CLEAR the DTCs. TEST the system for normal operation. For all other concerns, GO to B17. INSTALL a new fuel tank transfer tube, fuel pump module or fuel level sensor as necessary. REFER to Section CLEAR the DTCs. REPEAT the self test. B17 CHECK THE FUEL PUMP MODULE AND FUEL LEVEL SENSOR - Inspect the fuel pump module and fuel level sensor connector. - Repair: - corrosion (install new connector or terminals - clean module pins) - damaged pins - install new terminals/pins - pushed-out pins - install new pins as necessary - Reconnect the fuel pump module and fuel level sensor connector. Make sure they seat and latch correctly. - Operate the system and determine if the concern is still present. Is the concern still present? GO to B18. The system is operating correctly at this time. The concern may have been caused by component connections. ADDRESS the root cause of any connector or pin issues. 15/20

16 B18 CHECK THE FUEL PUMP MODULE AND FUEL LEVEL SENSOR 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 assembly and fuel level sender. Refer to Section Measure the resistance 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? GO to B21. For the fuel pump module, GO to B19. For the fuel level sensor, GO to B20. B19 CHECK THE FUEL PUMP MODULE SIGNAL AND RETURN CIRCUITS FOR A HIGH RESISTANCE - Ignition OFF. - Disconnect:IPC (Instrument Panel Cluster) C Connect a fused jumper wire between the fuel pump module C3127-1, circuit RMC32 (GN/BU), harness side and the fuel pump module C3127-2, circuit 16/20

17 VMC11 (YE/VT), harness side. - Measure the resistance between the IPC (Instrument Panel Cluster) C220-15, circuit VMC11 (YE/VT), harness side and the IPC (Instrument Panel Cluster) C220-2, circuit RMC32 (GN/BU), harness side. Is the resistance less than 5 ohms? GO to B22. REPAIR the circuits for high resistance. TEST the system for normal operation. B20 CHECK THE FUEL LEVEL SENSOR SIGNAL AND RETURN CIRCUITS FOR A HIGH RESISTANCE 17/20

18 - Connect a fused jumper wire between the fuel level sensor C3270-1, circuit RMC33 (WH/VT), harness side and the fuel level sensor C3270-2, circuit VMC23 (GN/OG), harness side. - Measure the resistance between the IPC (Instrument Panel Cluster) C220-14, circuit VMC23 (GN/OG), harness side and the IPC (Instrument Panel Cluster) C220-1, circuit RMC33 (WH/VT), harness side. Is the resistance greater than 10,000 ohms? GO to B22. REPAIR the circuits for high resistance. TEST the system for normal operation. B21 CHECK THE FUEL LEVEL SENDER (FLOAT AND CARD) 18/20

19 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. - Disconnect the fuel level sender input wire from the fuel pump assembly or fuel level sensor. - 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? INSTALL a new fuel pump assembly or fuel level sensor. REFER to Section CLEAR the DTCs (Diagnostic Trouble Codes). INSTALL a new fuel level sender (float and card). REFER to Section CLEAR the DTCs (Diagnostic Trouble Codes). B22 CHECK FOR CORRECT IC (Instrument Cluster) OPERATION - Disconnect the IC (Instrument Cluster) connector. - Check for: - corrosion - damaged pins 19/20

20 - pushed-out pins - Connect the IC (Instrument Cluster) connector and make sure it seats correctly. - Operate the system and verify the concern is still present. Is the concern still present? INSTALL a new IC (Instrument Cluster). REFER to Instrument Cluster (IC) See: Instrument Cluster / Carrier > Removal and Replacement > Instrument Cluster (IC).TEST the system for normal operation. 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. 20/20

Instrumentation, Message Center and Warning Chimes

SECTION 413-01: Instrumentation, Message Center, and Warning Chimes 2009 Mustang Workshop Manual DIAGNOSIS AND TESTING Procedure revision date: 07/15/2009 Instrumentation, Message Center and Warning Chimes