P0461

Diagnostic Chart:

Wiring Diagram:

Circuit Description

The Powertrain Control Module (PCM) uses the fuel level input from the fuel level sensor to calculate expected vapor pressures within the fuel system. Vapor pressures vary as the fuel level changes. Vapor pressure is critical to determining if the EVAP system is operating properly. Fuel level is also used to determine if the fuel level is too high or too low in order to be able to accurately detect EVAP system faults.

Conditions for Setting the DTC

^ Fuel level change check: maximum to minimum is less than 2 gallons.

^ Condition present once per drive cycle.

Action Taken When the DTC Sets

^ The Malfunction Indicator Lamp (MIL) will illuminate after two consecutive ignition cycles in which the diagnostic runs with the fault active.

^ The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC

^ The MIL will turn OFF after three consecutively passing cycles without a fault present.

^ A History DTC will clear after 40 consecutive warm-up cycles without a fault.

^ DTCs can be cleared by using a scan tool or by disconnecting the PCM battery feed.

Diagnostic Aids

Check for any of the following conditions:

^ If a DTC P0463 is also displayed, diagnose that DTC first.

^ A poor connection at the PCM. Inspect the harness connectors for backed out terminal, improper mating, broken locks, improperly formed or damaged terminals, and a poor terminal to wire connection.

^ A damaged wiring harness. Inspect the wiring harness for damage and repair as necessary.

^ A stuck fuel level sensor may cause a DTC P0461 to set.

Resistance checks for the fuel level sensor: At Empty = 100 ohms or over, At Half full = about 32.5 ohms, At Full 10 ohms or less.

If the DTC P0461 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions since the DTC was last set. This may assist in determining how often the DTC sets.

If any wiring repairs need to be made, Refer to Repair Procedures in Electrical Diagrams.

Test Description

The numbers below refer to the step numbers on the Diagnostic Table.

1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

2. Determine if a fault is present. Reviews the Freeze Frame data to determine when the DTC set. Always record this information.

7. If the fuel level gauge which is in the I/P cluster assembly is stuck at empty, it may be caused by a short to ground in the fuel level sensor signal wire.