Dodge Ram Truck 1500-2500-3500. Manual — part 899

P0463-FUEL LEVEL SENSOR 1 CIRCUIT HIGH (CONTINUED)

For the Engine circuit diagram (Refer to 9 - ENGINE - SCHEMATICS AND DIAGRAMS).

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
Ignition on and battery voltage above 10.4 volts.

•

Set Condition:
The fuel level sensor signal voltage at the PCM goes above 4.9 volts for more than 90 seconds. One Trip
Fault. Three good trips to turn off the MIL.

Possible Causes

(N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

(N4) FUEL LEVEL SIGNAL CIRCUIT OPEN

(K900) SENSOR GROUND CIRCUIT OPEN

FUEL LEVEL SENSOR

PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).

Diagnostic Test

1.

FUEL LEVEL SENSOR VOLTS ABOVE 4.9 VOLTS

NOTE: Diagnose any Bus Message failures before continuing.
Ignition on, engine not running.

With a scan tool, read the Fuel Level Sensor voltage.

Is the Fuel Level Sensor voltage above 4.9 volts?

Yes

>> Go To 2

No

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

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P0463-FUEL LEVEL SENSOR 1 CIRCUIT HIGH (CONTINUED)

2.

FUEL LEVEL SENSOR

Turn the ignition off.

Disconnect the Fuel Pump Module electrical harness connector.

Ignition on, engine not running.

Connect a jumper wire between the (N4) Fuel Level Signal circuit and
the (K900) Sensor Ground circuit in the Fuel Pump Module harness
connector.

With the scan tool, read the Fuel Level Sensor voltage.

Did the Fuel Level Sensor voltage change from above 4.8 volts
to below 0.4 of a volt with the jumper wire installed?

Yes

>> Replace the Fuel Level Sensor.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Go To 3

NOTE: Remove the jumper wire before continuing.

3.

(N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

Turn the ignition off.

Disconnect the C3 PCM harness connector.

Ignition on, engine not running.

Measure the voltage on the (N4) Fuel Level Signal circuit in the Fuel
Pump Module harness connector.

Is the voltage above 0 volts?

Yes

>> Repair the short to battery voltage in the (N4) Fuel Level

Signal circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Go To 4

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P0463-FUEL LEVEL SENSOR 1 CIRCUIT HIGH (CONTINUED)

4.

(N4) FUEL LEVEL SIGNAL CIRCUIT OPEN

Turn the ignition off.

CAUTION: Do not probe the PCM harness connectors. Probing
the PCM harness connectors will damage the PCM terminals
resulting in poor terminal to pin connection. Install Miller Special
Tool #8815 to perform diagnosis.
Measure the resistance of the (N4) Fuel Level Signal circuit from the
Fuel Pump Module harness connector to the appropriate terminal of
special tool #8815.

Is the resistance below 5.0 ohms?

Yes

>> Go To 5

No

>> Repair the open in the (N4) Fuel Level Signal circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

5.

(K900) SENSOR GROUND CIRCUIT OPEN

Measure the resistance of the (K900) Sensor Ground circuit from the
Fuel Pump Module harness connector to the appropriate terminal of
special tool #8815.

Is the resistance below 5.0 ohms?

Yes

>> Go To 6

No

>> Repair the open in the (K900) Sensor Ground circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

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P0463-FUEL LEVEL SENSOR 1 CIRCUIT HIGH (CONTINUED)

6.

PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.

Were there any problems found?

Yes

>> Repair as necessary.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Replace and program the Powertrain Control Module per Service Information.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

DR/DH

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