Circuit Description
Battery voltage is supplied to the evaporative emission (EVAP) canister vent solenoid valve. The control module grounds the EVAP canister vent solenoid valve control circuit to close the valve by means of an internal switch called a driver. The scan tool displays the commanded state of the EVAP canister vent solenoid valve as ON or OFF. The control module monitors the status of the driver. If the control module detects voltage between 4.6-6.6 on the control circuit when the driver is commanded OFF, this DTC sets.
The following table illustrates the relationship between the ON and OFF states, and the OPEN or CLOSED states of the EVAP canister vent solenoid valve.
Control Module Command | EVAP Canister Vent Solenoid Valve Position |
|---|---|
ON | CLOSED |
OFF | OPEN |
Conditions for Running the DTC
| • | The engine speed is more than 40 RPM. |
| • | The system voltage is between 7.5-17.3 volts. |
Conditions for Setting the DTC
| • | The control module detects between 4.6-6.6 volts on the control circuit when the driver is commanded OFF. |
| • | The fault is present for 0.5 seconds. |
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the DTC
| • | A current DTC Last Test Failed clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. |
| • | Clear the DTC with a scan tool. |
Diagnostic Aids
| • | EVAP canister vent solenoid resistance is 18-27 ohms |
| • | To locate an intermittent problem, with a scan tool, command the EVAP canister vent solenoid valve ON and OFF with the ignition ON and the engine OFF. Wiggling wires while listening for the EVAP canister vent solenoid valve to sop clicking may locate a shorted valve or the area where a short to voltage in the wiring may exist. |
| • | For intermittent conditions refer to Intermittent Conditions |
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 | |
2 |
Do you hear or feel a click from the EVAP canister vent solenoid valve when the valve is commanded ON and OFF? | Go to Step 3 | Go to Step 4 |
3 |
Did the DTC fail this ignition? | Go to Step 4 | Go to Diagnostic Aids |
4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 9 |
5 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 6 |
6 | Test the control circuit of the EVAP canister vent solenoid valve for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 8 |
7 | Test for an intermittent and for a poor connection at the EVAP canister vent solenoid 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 12 | Go to Step 10 |
8 | Test 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 12 | Go to Step 11 |
9 | Repair the open in the battery voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 12 | -- |
10 | Replace the EVAP canister vent solenoid valve. Refer to Evaporative Emission Canister Vent Solenoid Valve Replacement . Did you complete the replacement? | Go to Step 12 | -- |
11 | Replace the control module. Refer to Engine Control Module Replacement . Did you complete the replacement? | Go to Step 12 | -- |
12 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 13 |
13 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK | |
