P0463

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. These vapor pressures vary as the fuel level changes. The vapor pressure importance 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 to be able to accurately detect EVAP system failures.

Conditions for Setting the DTC

- Voltage range check: The voltage greater than a specified value after extended driving.

- Condition present for 0.5 seconds.

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.

- The PCM will enter the Fail-Safe Function and operate as if the fuel level is full.

Conditions for Clearing the MIL/DTC

- The MIL will turn off after three consecutive drive cycles without a fault present.

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

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

Diagnostic Aids

Check for the following conditions:

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

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

If a DTC P0463 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 Diagrams/Electrical.

Test Description

The numbers below refer to the step numbers in 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. Review the Freeze Frame data to determine when the DTC set. Always record this information.