Canister Purge Control Valve: Testing and Inspection

Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-, Testing







Special tools and equipment
- VAG 1526 A
- VAG 1527 B
- VAG 1594 A
- VAG 1598/31
- VAS 5051 with VAS 5051/1

Testing for leaks
Evaporative emission (EVAP) canister purge regulator valve -N80- remains closed when it is not receiving any current.
- Disconnect hoses from EVAP valve but leave the electrical connector plugged in.
- Connect an auxiliary hose to one of the connections on the EVAP valve.
- Connect the vehicle diagnostic, testing and information system VAS 5051, Vehicle Diagnostic, Testing and Information System VAS 5051, Connecting and Selecting Functions , and select the vehicle system "01 - Engine electronics" from the menu. When doing this the engine should be idling.
- Start output diagnostic test mode and select Evaporative emission (EVAP) canister purge regulator valve -N80-.







Display on VAS 5051:
A - 1st control element in test
1 - Evaporative emission (EVAP) canister purge regulator valve -N80-
- The valve should click...
- ...and open and close (can be checked by blowing into auxiliary hose).

If valve does not click:
- Test internal resistance of EVAP valve.

If the valve does not open and close properly:
- Replace Evaporative emission (EVAP) canister purge regulator valve-N80-.

Testing internal resistance
- Unplug connector on EVAP valve.







- Connect multimeter between contacts 1 and 2 of valve (resistance measurement range).
- Specification: 22 to 30 Ohms

If the specification is not attained:
- Replace Evaporative emission (EVAP) canister purge regulator valve-N80-.

If the specification is obtained:
- Test voltage supply.

Testing voltage supply

Requirements for test:
- Fuse for EVAP valve OK.

- Fuel pump relay OK. Testing.

NOTE: The EVAP valve receives its voltage supply via the fuel pump relay.

- Unplug connector on EVAP valve.







- Connect VAG 1527 B voltage tester as follows:

Connector Contact Measure against
1 Engine Ground

- Operate the starter briefly. (The engine can be allowed to start.)
- The LED should light up.

If the LED does not light up:
- Test for open circuit in wiring connection between fuel pump relay and contact 1 on connector via fuse
- Correct any open circuits.

If the LED lights up:
- Test activation.

Checking activation







- Connect VAG 1527 B voltage tester to contact 1 (positive) and contact 2 of the connector.
- Start output diagnostic test mode and select evaporative emission (EVAP) canister purge regulator valve -N80.
- The LED should flash.

If the LED lamp does not flash or lights up continuously:
- Connect test box VAG 1598/31 to wiring harness for engine control module. Do not connect to the engine control module itself. Scan Tool Testing and Procedures







- Test for open circuit and short to positive or Ground in the following wiring connections:

Connector Contact Test box VAG 1598/31 Socket
2 64

- Correct short circuit or open circuit if necessary.

If the wiring is OK:
- Install a new engine control module