P04AC

P04AC-EVAP SYSTEM PURGE CONTROL VALVE 2 CIRCUIT LOW

For a complete wiring diagram, refer to the Wiring Information.





- When Monitored:
Continuously with the ignition on.

- Set Condition:
The Powertrain Control Module (PCM) detects that the driver circuit voltage is too low.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

Diagnostic Test

1. ACTIVE DTC
1. Turn the ignition on, engine not running.
2. With the scan tool, View DTCs.

Is the DTC active?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

2. CHECK THE (F344) FUSED ASD RELAY OUTPUT CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Disconnect the OBD Vent Valve harness connector.
2. Using a 12-volt test light, probe the (F344) Fused ASD Relay Output circuit at the OBD Vent Valve harness connector.

NOTE: The test light should be illuminated and bright.

Is the test light illuminated and bright?

Yes

- Go To 3

No

- Repair the (F344) Fused ASD Relay Output circuit for an open or short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

3. CHECK THE (K71) OBD VENT VALVE DRIVER CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Measure the resistance of the (K71) OBD Vent Valve Driver circuit between the OBD Vent Valve harness connector and the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

- Repair the (K71) OBD Vent Valve Driver circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

4. CHECK THE (K71) OBD VENT VALVE DRIVER CIRCUIT FOR A SHORT TO GROUND
1. Measure the resistance between ground and the (K71) OBD Vent Valve Driver circuit at the OBD Vent Valve harness connector.

Is the resistance above 10k Ohms?

Yes

- Go To 5

No

- Repair the (K71) OBD Vent Valve Driver circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. CHECK THE OBD VENT VALVE
1. Measure the resistance of the OBD Vent Valve.

NOTE:
Connect the leads across the terminals of the valve (component side). It is best to measure the resistance of the valve at ambient temperature if possible.

Is the resistance between 36.0 Ohms and 44.0 Ohms?

Yes

- Replace the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Replace the OBD Vent Valve.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.