Dodge Ram Truck 1500-2500-3500. Manual — part 1242

P0462-FUEL LEVEL SENDING UNIT VOLTS TOO LOW (CONTINUED)

3.

(N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO GROUND

Turn the ignition off.

Disconnect the C3 PCM harness connector.

Measure the resistance between ground and the (N4) Fuel Level Sig-
nal circuit in the Fuel Pump Module harness connector.

Is the resistance below 100 ohms?

Yes

>> Repair the short to ground in the (N4) Fuel Level Signal

circuit.

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

No

>> Go To 4

4.

(N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT

Measure the resistance between the (N4) Fuel Level Signal circuit and
the (K900) Sensor Ground circuit in the Fuel Pump Module harness
connector.

Is the resistance below 5.0 ohms?

Yes

>> Repair the short between the (K900) Sensor Ground cir-

cuit and the (N4) Fuel Level Signal circuit.

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

No

>> Go To 5

5.

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)

9 - 1890

ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

DR/DH

P0463-FUEL LEVEL SENSOR 1 CIRCUIT HIGH

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

9 - 1891

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)

9 - 1892

ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

DR/DH

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

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

9 - 1893