Canister Purge Solenoid: Testing and Inspection
Evaporative Emission (EVAP) Canister Purge Solenoid Valve - N115 -, Checking
Special tools and equipment
- VAG1526A
- VAG15278
- VAG1594A
- VAG1598/31
- VAS5051 with VAG5051/1
or
- VAG1551 with VAG1551/3A
Checking function
NOTE:
- Checking seal (performing leak testing). Testing and Inspection
- For leaking Evaporative Emission (EVAP) canister purge solenoid valve -N115-, replace O-rings, Fig 9. Service and Repair
During leak testing, the Evaporative Emission (EVAP) canister purge solenoid valve -N115- will be activated and thereby closed. Valve clicks audibly during this process.
Initiate leak testing as follows:
- Connect VAS5051 tester to vehicle with VAS5051/1 diagnostic wire. Alternately, VAG1551 scan tool can also be attached using VAG1551/3A adapter.
NOTE: The following description only explains implementation of On Board Diagnostic (OBD) using VAG1551 scan tool. When using the VAS5051 tester, observe the tester's instructions for use.
Indicated on display 1)
V.A.G - ON BOARD DIAGNOSTIC HELP
1 - Rapid data transfer
2 - Blink code output
1) Operating modes 1 and 2 are displayed alternately
- Start engine and run at idle.
- Press button 1 to select "Rapid data transfer" operating mode 1.
Rapid data transfer HELP
Insert address word XX
- Press buttons -0- and -1- to select "Engine Electronics" and press -0- button to confirm input.
- Press button.
Indicated on display
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -3- to select "Output Diagnostic Test Mode".
Indicated on display
Rapid data transfer Q
03 - Output Diagnostic Test Mode
- Press -Q- button to confirm input.
Indicated on display
Output Diagnostic Test Mode ->
Recirculating valve for turbochar -N249
- Press button
Indicated on display
Output Diagnostic Test Mode ->
EVAP canister purge regulator val - N115
This solenoid valve will be activated for approximately 1 minute (clicks), unless output Diagnostic Test Mode is terminated earlier by pressing the -> button.
NOTE: Clicking noise of valve can only be heard near the rear axle.
If valve does not click:
- Check internal resistance of Evaporative Emission (EVAP) canister purge solenoid valve -N115-.
Checking internal resistance
Vehicles with Front Wheel Drive (FWD):
- Remove EVAP canister cover, below, at spare tire compartment (arrows).
Vehicles with All Wheel Drive (AWD):
- Disconnect exhaust system at clamping sleeve (arrows).
- Remove right rear bracket for exhaust system.
- Disengage rear portion of exhaust system at brackets.
NOTE: The exhaust system release element must not be bent more than 10 , otherwise it could be damaged.
- Remove rear heat shield and bracket for exhaust system (arrows).
- Remove rear nut (arrow) of cover for EVAP canister.
- Fold cover for EVAP canister down at rear edge.
All:
- Disconnect electrical harness connector (arrow).
NOTE: Illustration depicts a vehicle with Front Wheel Drive (FWD).
- Connect multimeter at valve for resistance measurement.
- Specified value: 22-26 Ohms
If specified value is not obtained:
- Replace Evaporative Emission (EVAP) canister purge regulator valve -N80-.
If specified value is obtained:
- Check voltage supply.
Checking voltage supply
NOTE: Voltage supply test of Evaporative Emission (EVAP) canister purge solenoid valve -N115- is performed via Fuel Pump (FP) relay.
Test requirements
NOTE:
- Parking brake engaged
- Vehicles with manual transmission: shift lever in neutral.
- Vehicles with automatic transmission: selector lever in P or N.
- Fuse for Evaporative Emission (EVAP) Canister Purge Regulator Valve -N115- OK
- Disconnect connector at Evaporative Emission (EVAP) canister purge solenoid valve -N115-.
- Connect VAG1527B voltage tester as follows:
Electrical harness connector Measure to
terminal number
1 Ground (GND)
- Operate starter briefly (OK for engine to start).
- LED must light.
If LED does not light:
- Check electrical wire connection from terminal / via fuse to Fuel Pump (FP) relay for open circuit.
- Repair open circuit if necessary.
If wire connection is OK:
- Check Fuel Pump (FP) relay.
If LED lights:
- Check activation.
Checking activation
NOTE: Voltage supply OK
- Connect VAG1527B voltage tester to connector terminals 1 (B+) and 2.
- Initiate output Diagnostic Test Mode (DTM) and activate evaporative emission (EVAP) canister purge solenoid valve -N115-.
- LED must blink
If LED does not blink:
- Switch ignition off.
- Remove wiper arms.
- Remove plenum chamber cover and set aside on windshield side.
- Disengage locking lugs and remove control module connector.
- Connect VAG1598/31 test box to connector of wiring harness Ground (GND)/clip (arrow) at test box must be clipped to battery negative. Engine Control Module (ECM) must not to be attached.
- Check the following wire connection for open circuit and short circuit to Ground (GND) and B+:
Electrical Harness connector VAG1598/31 test box Bushing
terminal
2 116
- Repair open circuit or short circuit if necessary.
If wire connection is OK:
- Replace Engine Control Module (ECM).
After completing work:
- Generate readiness code.