Pinpoint Tests AF: The Water In Fuel Message Center Indicator Is Never/Always On
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test AF: The Water In Fuel Message Center Indicator Is Never/Always On (Diesel Only)
Refer to Wiring Diagram Set 26, Electronic Engine Controls - 6.0L Diesel for schematic and connector information Diagrams By Number.
Normal Operation
The water in fuel data is transmitted to the Instrument Panel Cluster (IPC) from the PCM over the High Speed Controller Area Network (HS-CAN). The water in fuel sensor receives a reference voltage from the PCM through independent input and return circuits. When water is detected in the fuel, the water in fuel sensor pulls the reference voltage low to the PCM. The PCM then sends a command to the IPC to illuminate the message center indicator.
If the water in fuel status is missing for less than 5 seconds, the water in fuel indicator remains in the last on/off state, based upon the last known good water in fuel status message received.
If the water in fuel data is missing for more than 5 seconds, the IPC sets DTC U0100:00 in continuous memory and defaults the water in fuel indicator off.
NOTE: If DTC U0100:00 is set in the IPC, other observable symptoms may be an inoperative speedometer, tachometer or odometer.
This pinpoint test is intended to diagnose the following:
- Water in fuel condition
- Wiring, terminals or connectors
- Water in fuel sensor
- PCM
- IPC
PINPOINT TEST AF: THE WATER IN FUEL MESSAGE CENTER INDICATOR IS NEVER/ALWAYS ON (DIESEL ONLY)
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AF1 VERIFY THE OPERATION OF THE POWERTRAIN MALFUNCTION (WRENCH) AND ENGINE OVER-TEMPERATURE MESSAGE CENTER INDICATORS
- Ignition OFF.
- Disconnect: In-Line C219 .
- Ignition ON.
- NOTE: If multiple warnings are present, the message center indicators rotate through each of the warnings. Allow the displays to rotate through each display while determining whether the powertrain malfunction (wrench) and over-temperature message center indicators are active.
- Observe the message center or integrated display area of the IPC with the PCM connected and disconnected.
- Does the powertrain malfunction (wrench) message center warning indicator remain off when the PCM is connected and become active with the PCM disconnected?
Yes
If the water in fuel message center warning indicator is never on, GO to AF2.
If the water in fuel message center warning indicator is always on, GO to AF3.
No
INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). TEST the system for normal operation.
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AF2 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST
- Check for recorded IPC DTCs from the self-test.
- Are any DTCs recorded?
Yes
For DTC U0100:00, GO to Pinpoint Test AV. Pinpoint Tests AV: DTC U0100:00
For all other DTCs, REFER to DTC Charts. Instrumentation, Message Center and Warning Chimes
No
GO to AF5.
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AF3 CHECK THE WATER IN FUEL SENSOR OPERATION (ALWAYS ON)
- Ignition OFF.
- Disconnect: Water In Fuel Sensor C4350.
- Ignition ON.
- Does the water in fuel message center indicator turn off?
Yes
CHECK the fuel system for water contamination.
If water contamination exists, drain the water from the fuel system. REFER to Fuel Delivery and Air Induction. TEST the system for normal operation.
If no water contamination is found, INSTALL a new water in fuel sensor. TEST the system for normal operation.
No
GO to AF4.
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AF4 CHECK THE WATER IN FUEL INPUT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: PCM C1381b.
- Measure the resistance between the PCM C1381b-15, circuit VE823 (BU/BN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to AF8.
No
REPAIR the circuit. TEST the system for normal operation.
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AF5 CHECK THE WATER IN FUEL SENSOR OPERATION (NEVER ON)
- Ignition OFF.
- Disconnect: Water In Fuel Sensor C4350.
- Connect a fused jumper wire between the water in fuel sensor C4350-1, circuit VE823 (BU/BN), harness side and ground.
- Ignition ON.
- Wait approximately 4 minutes.
- Does the water in fuel message center indicator illuminate?
Yes
GO to AF6.
No
GO to AF7.
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AF6 CHECK THE WATER IN FUEL RETURN FOR AN OPEN
- Ignition OFF.
- Disconnect: PCM C1381b.
- Measure the resistance between the water in fuel sensor C4350-2, circuit RE407 (YE/VT), harness side and the PCM C1381b-33, circuit RE407 (YE/VT), harness side.
- Is the resistance less than 5 ohms?
Yes
VERIFY that the fuel system has sufficient water contamination to turn on the water in fuel message center indicator.
If sufficient water contamination exists, INSTALL a new water in fuel sensor. TEST the system for normal operation.
If insufficient water contamination is found, the system is operating normally at this time.
No
REPAIR the circuit. TEST the system for normal operation.
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AF7 CHECK THE WATER IN FUEL INPUT FOR AN OPEN
- Ignition OFF.
- Disconnect: PCM C1381b.
- Measure the resistance between the water in fuel sensor C4350-1, circuit VE823 (BU/BN), harness side and the PCM C1381b-15, circuit VE823 (BU/BN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to AF8.
No
REPAIR the circuit. TEST the system for normal operation.
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AF8 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the PCM 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 PCM. REFER to Computers and Control Systems. 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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