EVAP Canister Purge Valve, Checking

EVAP Canister Purge Valve, Checking

Special tools, testers and auxiliary items required
- Multimeter.
- Wiring diagram.

Test requirements
- Fuse S234 OK.
- Fuel Pump (FP) Relay J17 OK.
- The ignition switched off.

NOTE: Voltage for the Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 is supplied by the Fuel Pump (FP) Relay J17.

Test procedure
- Perform a preliminary check to verify the customers complaint. General Diagnosis

Start diagnosis
- Disconnect the Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 electrical harness connector.

Checking internal resistance







- Using a Multimeter, check the resistance between terminals 1 and 2 of the Evaporative Emission (EVAP) Canister Purge Regulator Valve N80.

Specified value: 22,0 to 30,0 Ohms.

If the specified value was not obtained:
- Replace the Evaporative Emission (EVAP) Canister Purge Regulator Valve N80.

If the specification is obtained:

Checking voltage supply







- Using a Multimeter, check the electrical harness connector terminal 1 to Ground (GND) for voltage.

Evaporative Emission (EVAP) Measure to
Canister Purge Regulator
Valve N80 Electrical
Harness connector Terminal
1 Engine Ground (GND)

- Operate the starter briefly.

Specified value: battery voltage.

If the specified value was not obtained:
- Check the wiring connection from the Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 electrical harness connector terminal 1 to the Fuel Pump (FP) Relay J17 terminal 19/86 for an open circuit or a short circuit to Battery positive (+).
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the wiring connection.

If the specified value was obtained:

Checking wiring

If the manufacturers test box is being used. Perform the following step.
- Install the test box VAG1598/31.

If the manufacturers test box is not being used. Perform the following step.
- Remove the Motronic Engine Control Module (ECM) J220.







- Using a Multimeter, check the Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 electrical connector terminal 2 to the Motronic Engine Control Module (ECM) J220 electrical harness connector terminal 64 for resistance.

Evaporative Emission (EVAP) Motronic Engine Control Module (ECM)
Canister Purge Regulator J220 electrical harness connector
Valve N80 Electrical harness terminal test box socket
connector terminal
2 64

Specified value: 1.5 Ohms.

If the specification was not obtained:
- Check the wiring for a short circuit to Battery positive (+), Ground (GND) or an open circuit.
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the wiring connection.

If the specification was obtained:
- Erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
- Perform a road test to verify repair.

If the DTC does not return:
Repair complete, Generate readiness code. Readiness Code
- End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:
- Replace the Motronic Engine Control Module (ECM) J220.
- Assembly is performed in the reverse of the removal.

Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
1. Check the DTC memory. Diagnostic Mode 03 - Read DTC Memory
2. If necessary, erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
3. If the DTC memory was erased, generate readiness code.

End of diagnosis