Dodge Ram Truck 1500-2500-3500. Manual — part 1083

P0461-Fuel Level Unit No Change Over Time (CONTINUED)

3.

FUEL LEVEL SENSOR

Measure the resistance between the sensor (N4) signal circuit and (K900) return circuit while moving the sensor
float arm.

Does the resistance level change as you move the sensor arm?

Yes

>> Go To 4

No

>> Replace the fuel level sensor.

Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

4.

INSIDE OF FUEL TANK OBSTRUCTED DAMAGED

Visually inspect the inside of the fuel tank for obstructions.

Is the inside of the fuel tank damaged or obstructing the fuel level sensor?

Yes

>> Test Complete.

No

>> Replace the fuel tank.

Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

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ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL

DR/DH

P0462-LOW VOLTAGE DETECTED AT THE FUEL LEVEL SENSOR

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL

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P0462-LOW VOLTAGE DETECTED AT THE FUEL LEVEL SENSOR (CONTINUED)

For the Engine circuit diagram (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CON-
TROL MODULE - SCHEMATIC - ELECTRICAL)

For a complete wiring diagram Refer to Section 8W.

•

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

•

Set Condition:
The signal voltage from the sensor falls below a calibrated value for a calibrated amount of time.

Possible Causes

FUEL LEVEL SENSOR

(N4) SIGNAL CIRCUIT OPEN

(N4) SIGNAL CIRCUIT SHORTED TO VOLTAGE

INTERMITTENT CONDITION

ECM

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

Diagnostic Test

1.

FUEL LEVEL SENSOR

Turn the ignition off.

Disconnect the Fuel Level Sensor harness connector.

NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the sensor across the (N4) signal circuit and (K900) return circuit.

Is the resistance less than 10 ohms?

Yes

>> Go To 2

No

>> Replace the fuel level sensor.

Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

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ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL

DR/DH

P0462-LOW VOLTAGE DETECTED AT THE FUEL LEVEL SENSOR (CONTINUED)

2.

(G8) SIGNAL CIRCUIT OPEN

Disconnect the ECM harness connectors.

NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the (N4) signal circuit between the ECM
harness connector and the sensor harness connector.

Is the resistance less than 10 ohms?

Yes

>> Go To 3

No

>> Repair the open (N4) signal circuit.

Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

3.

(G8) SIGNAL CIRCUIT SHORTED TO VOLTAGE

Measure the voltage between the (N4) signal circuit and battery neg-
ative.

Is the voltage greater than 1 volt?

Yes

>> Repair the (N4) signal circuit shorted to voltage.

Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

No

>> Go To 4

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL

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