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P0444







P0444
EVAP Canister Purge Valve - open circuit

Function
Hydrocarbons from fuel evaporation in the fuel tank are not discharged into the open air but collected by an Evaporative Emission (EVAP) Canister. The EVAP Canister is installed in the left rear wheel well . To recycle the hydrocarbons into the combustion process, the EVAP Canister is purged and the activated charcoal is regenerated. Between the EVAP Canister and the air intake system, an Evaporative Emission (EVAP) Canister Purge Valve is installed. The direction of flow is marked on the plastic housing by an arrow.

Diagnosis condition
The diagnosis of the EVAP Canister Purge Valve is active when the engine temperature is higher than 80.25°C and conditions exist for the purging of the EVAP Canister





Wiring diagram.

NOTE: If in addition to the break in the wiring of the EVAP Canister Purge Valve, also the IAC Valve, the fuel injectors, the Secondary Air Injection Check Valve, and other electrical consumers are without power, the power supply via the ECM relay and the engine wiring harness has to be checked as per wiring diagram.





Diagnosis procedure
Power supply for EVAP Canister Purge Valve
1. Switch ignition off.
2. Remove connectors for ECM and EVAP Canister Purge Valve
3. Connect voltmeter with test lead to connector of EVAP Canister Purge Valve.
4. With jumper wire, connect ECM connector pin 27 (activation of the ECM relay) and pin 61 (ground for EVAP Canister Purge Valve) to Ground (GND). Display: 12 V

- If OK.: Check solenoid of EVAP Canister Purge Valve.
- If not OK: Check resistance of cable connection on plus side of EVAP Canister Purge Valve.

Check resistance of cable connection on plus side of EVAP Canister Purge Valve.
1. Switch ignition off.
2. Remove connector of EVAP Canister Purge Valve.
3. Remove ECM relay at fuse/relay panel.
4. Connect ohmmeter between EVAP Canister Purge Valve, connector 1 (red/white wire) and ECM relay connector, pin 87. Display: < 10 ohms.

- If OK.: Check solenoid of EVAP Canister Purge Valve.
- If not OK.: Replace wiring harness.

Check resistance of cable connection for EVAP Canister Purge Valve, negative side
1. Switch ignition on.
2. Remove connector for EVAP Canister Purge Valve.
3. Connect ohmmeter between ECM connector, pin 61 and EVAP Canister Purge Valve, pin 2. Display: < 10 ohms.

- If OK.: Check solenoid of EVAP Canister Purge Valve.
- If not OK.: Replace wiring harness.

Check solenoid of EVAP Canister Purge Valve.
1. Switch ignition off.
2. Remove connector from EVAP Canister Purge Valve.
3. Connect ohmmeter with jumper cable to EVAP Canister Purge Valve. Display: approx. 30 ohms.

- If OK: Check ECM end stage.
- If not OK.: Replace EVAP Canister Purge Valve.

Check ECM end stage
1. Switch ignition off.
2. Connect Bosch L-Jetronik adapter cable 1684463093 between EVAP Canister Purge Valve and connector.

NOTE: The EVAP Canister Purge Valve is triggered only when the engine is at operating temperature. Triggering occurs after engine start-up within 250 sec.

3. Connect voltmeter to Bosch adapter cable.
4. Start engine.
5. Increase engine rpm and engine load. Display: > 2 V Depending on air volume passing through Mass Air Flow Sensor

- If OK.: End.
- If not OK.: Replace ECM.
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