Circuit Description
An ignition voltage is supplied directly to the evaporative emission (EVAP) canister purge valve. The EVAP canister purge valve is pulse width modulated (PWM). The scan tool displays the amount of ON time as a percentage. The control module monitors the status of the driver. The control module controls the EVAP canister purge valve ON time by grounding the control circuit via an internal switch called a driver. If the control module detects voltage on the control circuit when the driver is commanded ON, this DTC sets.
Conditions for Running the DTC
| • | The engine speed is more than 400 RPM. |
| • | The system voltage is between 8-18 volts. |
Conditions for Setting the DTC
| • | The control module detects voltage on the control circuit when the driver is commanded ON. |
| • | The fault is present for 50 seconds, cumulative during the drive cycle. |
Action Taken When the DTC Sets
| • | The control module will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test ran and failed. |
| • | The control module will store conditions which were present when the DTC set as Freeze Frame/Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC will clear after 40 consecutive warm-up cycles without a malfunction. |
| • | Clear the MIL and the DTC with a scan tool. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | |||
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | |
Do you hear or feel a clicking from the EVAP purge valve when the valve is commanded to 50 percent? | Go to Step 3 | Go to Step 4 | |
3 |
Does the DTC fail this ignition? | Go to Step 4 | Go to Intermittent Conditions |
4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 6 |
5 | Test the control circuit of the EVAP purge valve for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 7 |
6 | Inspect for an intermittent and for a poor connection at the EVAP purge valve. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 8 |
7 | Inspect for an intermittent and for a poor connection at the control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 9 |
8 | Replace the EVAP purge valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement . Did you complete the replacement? | Go to Step 10 | -- |
9 | Replace the control module. Refer to Engine Control Module Replacement . Did you complete the replacement? | Go to Step 10 | -- |
10 |
Does the DTC run and pass? | Go to Step 11 | Go to Step 2 |
11 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | System OK | |
