Canister Purge Control Valve: Testing and Inspection
Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-, Checking
Solenoid valve is closed when no voltage is present.
Checking activation:
Special tools and equipment
- VAG1551 scan tool (or VAG1552 mobile scan tool) with VAG1551/3B cable
Test requirements
- All fuses must be OK.
- Coolant temperature must be at least 80 °C, See Display group 04, display field 3
- No DTCs in DTC memory
Function test
- Connect VAG 1551 scan tool (VAG1552). Start engine and select the Engine Control Module (ECM) using address word 01. Connecting scan tool and selecting Engine Control Module (ECM):
Indicated on display:
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -8- to select "Read measuring value block" function 08. Press -Q- button to confirm input.
Indicated on display:
Read measuring value block HELP
Enter display group number XXX
- Press 0, 7 and 0 for the function "display group number 70", and then press Q to exit from input mode.
NOTE: TVV stands for Tank Ventilation Valve (Evaporative Emission canister purge regulator valve).
If display field 4 indicates "TVV not OK":
Indicated on display: (1 to 4 = display fields)
Read measuring value block 70 "
1 2 3 4
- Press button 4 to select "basic setting" function ("diagnostic of tank vent valve" will be initiated)
NOTE: Do not generate engine load during diagnostic or else it will be terminated and cannot be initiated again until after accelerator pedal is depressed.
If diagnostic is initiated by the Engine Control Module (ECM), the indication in display field 4 will jump from "Test OFF" to "Test ON".
Display Group 70:
- Initiate output Diagnostic Test Mode (DTM) and activate Evaporative Emission (EVAP) canister purge regulator valve -N80-:
- Evaporative Emission (EVAP) canister purge regulator valve -N80- must click audibly.
If valve does not click:
- Check voltage supply at Evaporative Emission (EVAP) canister purge regulator valve -N80-:
The valve clicks, but a malfunction is recognized anyway (valve opens but does not close):
- Check solenoid valve for soiling, replace if necessary.
- Check hose connection to EVAP canister, it may be kinked.
If the specified value "TVV OK" is obtained:
- Press -> button.
Indicated on display:
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -6- to select "End data transfer" function 06. Press -Q- button to confirm input.