P0460

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The PCM uses the 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 Emissions 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 EVAP system faults.


CONDITIONS FOR SETTING THE DTC

The fuel level has not changed more than 1.6% (4 counts) in 120 miles.


ACTION TAKEN WHEN THE DTC SETS

^ The PCM records the operating conditions at the time the diagnostic fails. The Failure Records buffers will store this information.

^ A history DTC is stored.

^ The fuel tank level defaults to 40%.


CONDITIONS FOR CLEARING THE DTC

^ A history DTC clears after 40 consecutive warm up cycles without a fault.

^ The scan tool can clear the DTC.


DIAGNOSTIC AIDS

Whenever a DTC P0460 is set along with an EVAP System DTC, the EVAP DTC can not be considered valid until DTC P0460 is repaired and cleared.


TEST DESCRIPTION

Number(s) below refer to the step number(s) on the Diagnostic Table.

1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the Freeze Frame Data and the Failure records on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. This information on the scan tool can be referred to later.

2. The fuel level display on the scan tool is displayed in percentage of fuel in the fuel tank. It is also important to know approximately how much fuel is in the tank prior to performing this step.

9. Before replacing the PCM, check terminals for improper mating, broken locks, or physical damage to the wiring harness. Replacement PCMs must be reprogrammed and the crankshaft position system variation procedure must be performed. Refer to the latest Techline information for programming procedures and also refer to the Crankshaft Position (CKP) System Variation Learn Procedure.