DTC Advanced Diagnostics: P0459 (3.0L Engine)
DTC P0459: Evaporative Emission (EVAP) Canister Purge Valve Circuit High Voltage
General Description
The evaporative emission (EVAP) canister purge valve is attached to the vacuum port between the intake manifold and the EVAP canister. The powertrain control module (PCM) turns the EVAP canister purge valve OFF when the engine coolant temperature is low. The PCM adjusts the amount of fuel vapor intake into the engine by controlling the EVAP canister purge valve. If the EVAP canister purge valve control terminal voltage level does not change correctly for a set time, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 5 seconds or more |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| 12 volt battery voltage [Battery] | 10.0 V | - |
| EVAP canister purge valve duty | 0.2 % | - |
[ ]: HDS Parameter
Malfunction Threshold
The EVAP canister purge valve control terminal voltage level is high for at least 5 seconds where it should be at low level when the current is applied to the EVAP canister purge valve.
Possible Cause
- EVAP canister purge valve PCS line short to power
- PCM internal circuit failure
Confirmation Procedure
Operating Condition
- Start the engine. Hold the engine speed [Engine Speed] at 3, 000 rpm without load (in P or N) until the radiator fan comes on.
- Let it idle for 5 minutes or more.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC, the freeze data, and the on-board snapshot are stored.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.