P0448

DTC P0448 EVAP Vent solenoid Circuit Short




Circuit Description
The canister purge solenoid valve is controlled by the Power Train Control Module (PCM). The PCM monitors vacuum level via the fuel tank pressure sensor input. At an appropriate time, the EVAP canister vent solenoid is "ON," allowing engine vacuum to draw a small vacuum on the entire evaporative emissions system.

Conditions for Setting the DTC
- The Ignition is "ON".
- Engine is running.
- System voltage is between 11.5 volts and 16 volts.

Action Taken When the DTC Sets
- The PCM will not illuminate the malfunction indicator lamp (MIL).
- The PCM will store conditions which were present when the DTC was set in the Failure Records data only.

Conditions for Clearing the MIL/DTC
- The PCM will turn the MIL "OFF" on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present.
- A history DTC P0448 will clear after 40 consecutive trip cycle during which the warm up cycles have occurred without a fault.
- DTC P0448 can be cleared using the Tech 2 "Clear Info" function or by disconnecting the PCM battery feed.

Diagnostic Aids
An intermittent may be caused by the following:
- Poor connections.
- Mis routed harness.
- Rubbed through wire insulation.
- Broken wire inside the insulation.

Check for the following conditions:
- Poor connection at PCM-Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
- Damaged harness-Inspect the wiring harness for damage. If the harness appears to be OK, observe the EVAP vent valve display on the Tech 2 while moving connectors and wiring harnesses related to the sensor.

A change in the display will indicate the location of the fault. If DTC P0448 cannot be duplicated, the information included in the Failure Records data can be useful in determined vehicle mileage since the DTC was last set.

If it is determined that the DTC occurs intermittently, performing the DTC P0448 Diagnostic Chart may isolate the cause of the fault.

Steps 1 - 7:

Test Description