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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2000 🢒 Sonoma Pickup - 2WD 🢒 Body and Accessories 🢒 Instrument Panel, Gauges, and Console 🢒 DTC P0461 Fuel Level Sensor Performance

Object Number: 387285 Size: MF
Engine Controls Components
Fuel Level and Fuel Tank Pressure Sensors
OBD II Symbol Description Notice
Powertrain Control Module Connector End Views
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The PCM uses a fuel level input in order to calculate the expected vapor pressures within the fuel system. These vapor pressures vary as the fuel level changes. The vapor pressure is critical in determining if the evaporative emission (EVAP) system is operating properly. The PCM also uses the fuel level in order to determine if the fuel level is too high or too low to be able to accurately detect an EVAP system malfunction.

Conditions for Running the DTC
    • The ignition is ON.
    • The system voltage is between 11.0 volts and 16.0 volts.

Conditions for Setting the DTC

Fuel level has not changed more than 1.6 percent in 193 km (120 miles).

Action Taken When the DTC Sets
    • The PCM will record the operating conditions during the time which the diagnostic fails. This information will store in the Failure Records buffer.
    • A history DTC is stored.

Conditions for Clearing the DTC
    • A history DTC clears after 40 consecutive warm up cycles without a fault.
    • The scan tool clears the DTC.

Diagnostic Aids
    • Inspect for the following conditions that may cause intermittents:
       - Poor electrical connections
       - Rubbed through wire insulation
       - A wire that is broken inside the wire insulation
    • Thoroughly inspect any circuitry that is suspected as causing the intermittent complaint. Inspect for the following conditions:
       - Backed out terminals
       - Improper mating
       - Broken locks
       - Improperly formed or damaged terminals
       - Poor terminal to wire connections
    • Before replacing the PCM, inspect the PCM electrical connector terminals for the following conditions:
       - Improper mating
       - Broken locks
       - Physical damage to the wiring harness

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. The Powertrain On-Board Diagnostic (OBD) System Check prompts you to complete some of the basic checks and to store the Freeze Frame and Failure Records data on the scan tool if applicable. This creates an electronic copy of the data captured when the malfunction occurred. The scan tool stores this data for later reference.

    2.

  2. Replacement PCMs must be reprogrammed and the Crankshaft Position System Variation Procedure must be performed. Refer to the latest Techline information for programming procedures.

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Turn ON the ignition, with the engine OFF.
  2. Install a scan tool.
  3. Determine whether DTCs P0462 or P0463 are set.

Are DTCs P0462 or P0463 set?

--

Go to DTC P0462 Fuel Level Sensor Circuit Low Voltage or to DTC P0463 Fuel Level Sensor Circuit High Voltage

Go to Step 3

3

  1. Turn OFF the ignition .
  2. Disconnect the fuel level sensor electrical connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Verify the fuel level on the scan tool.

Does the scan tool indicate the specified level?

100%

Go to Step 4

Go to Step 5

4

Connect a jumper wire between the following circuits:

    • Fuel level sensor ground
    • Fuel level sensor signal

Does the scan tool display the specified value?

0%

Go to Step 10

Go to Step 6

5

  1. Inspect the fuel level sensor circuit for a short to ground.
  2. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Was a repair necessary?

--

Go to Step 12

Go to Step 9

6

  1. Connect a test lamp to B+.
  2. Probe the fuel level sensor ground circuit.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 8

7

  1. Inspect the fuel level sensor signal circuit for the following conditions:
    2. • Open circuit
    • Poor electrical connection
  2. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Was a repair necessary?

--

Go to Step 12

Go to Step 9

8

  1. Inspect the fuel level sensor ground circuit for the following conditions:
    2. • Open circuit
    • Poor electrical connection
  2. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Was a repair necessary?

--

Go to Step 12

Go to Step 9

9

  1. Turn OFF the ignition .

    2. Important: The replacement PCM must be programmed.

  2. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 12

--

10

  1. Inspect the fuel level sensor electrical connector for the following conditions:
    2. • High circuit resistance
    • Poor electrical connection
  2. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Was a repair necessary?

--

Go to Step 12

Go to Step 11

11

  1. Turn OFF the ignition .
  2. Replace the fuel level sensor. Refer to Fuel Level Sensor Replacement .

Is the action complete?

--

Go to Step 12

--

12
  1. Use the scan tool in order to clear the DTCs.
  2. Start the engine.
  3. Idle the engine at the normal operating temperature.
  4. Operate the vehicle within the Conditions for Running this DTC as specified in the supporting text.

Does the scan tool indicate that this diagnostic has Ran and Passed?

--

Go to Step 13

Go to Step 2

13

Determine if any additional DTCs are set.

Does the scan tool display any DTCs that have not been diagnosed?

--

Go to applicable DTC table

System OK