Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 System, Checking For Leaks
Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 System, Checking For Leaks
Special tools, testers and auxiliary items required
- Evaporative Emissions Tester KLI 9210 (smoke tester)
- Hose adapter KLI 9210/55-2
- Vehicle Diagnosis, Testing and Info. System VAS 5051B , VAS 5052 or VAS 5053
- Hose Clamps Up to 25 mm dia. 3094
Test conditions:
- A leak was detected by Leak Detection Pump (LDP) V144 .
- Guided Fault Finding was performed with Vehicle Diagnosis, Testing and Info. System .
Evaporative Emissions Tester KLI 9210 preparation:
NOTE: Depending on the version, the appearance of the Evaporative Emissions Tester KLI 9210 may vary.
- Check on Evaporative Emissions Tester KLI 9210 whether there is enough fluid in smoke generator.
- Set valve - D - to "Hold".
- Open nitrogen bottle - H - .
- Connect measuring hose - G - on self-test connection - B -.
- Set valve - D - to "Test" .
- Using pressure reducer - J -, adjust pressure to 25 mbar (10 in. H(2)O).
- Set valve - D - to "Hold" .
- The pressure must now be maintained min. 2 minutes. If pressure is not maintained, check tester.
Fuel system, checking for leaks:
- Disconnect breather line - arrow - to Evaporative emission (EVAP) canister purge regulator valve N80 in engine compartment.
- Connect Adapter Hose KLI 9210/55-2 as shown between Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 and ventilation line.
- Connect measuring hose - G - on Evaporative Emissions Tester KLI 9210 to Adapter Hose KLI 9210/55-2 .
- Connect Evaporative Emissions Tester KLI 9210 to vehicle battery.
- Connect evaporative emissions tester to vehicle.
- Start engine and run at idle speed.
- Select OBD operating mode on evaporative emissions tester.
- Now select diagnostic mode 8 "Tank leak test" .
- Mark "Tank leak test" entry and press right arrow button --> to activate test.
NOTE:
- When diagnostic mode 8 "Tank leak test" is activated, leak detection pump and Evaporative Emission (EVAP) Canister Purge Solenoid Valve 2 N115 are closed for a maximum of 1000 seconds. The Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 is not activated. The entire system is now closed.
- If the engine control module stops the test, it can be reactivated by stopping the engine and restarting.
- Set valve - D - to "Test" . The fuel system is now filled with nitrogen.
- Observe pressure gauge - C - and flow meter - E - . If the flow quantity decreases and pressure climbs to 25 mbar (10 in. H(2)O), the fuel system is full.
NOTE: Depending on the level in the fuel tank, this procedure may take up to 3 minutes.
- After pressure has stabilized, set valve - D - to "Hold".
- The pressure must not drop below 20 mbar (8 in. H(2)O) after 5 minutes.
If no pressure decrease can be determined, end diagnostic mode 8 and check Leak Detection Pump (LDP) V144 pressure buildup .
If pressure does not build up or if positive pressure is not maintained for at least 5 minutes, locate leak as follows:
Allow engine to continue running at idle with diagnostic mode 8 activated.
- First check Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 for leaks. Clamp off hose to Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 with hose clamp - arrow - .
- Repeat pressure test by resetting valve - D - to "Test" .
- Observe pressure gauge and flow meter. If flow quantity decreases and pressure climbs to 25 mbar (10 in. H(2)O), the fuel system is full.
- After pressure has stabilized, set valve - D - to "Hold".
- If pressure now no longer falls, replace Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 .
If pressure still drops:
- Reset valve - D - to "Test" .
- While fuel system is being filled, press smoke generator button - I - for approx. one minute.
The fuel system is now under pressure and filled with smoke.
- Check all visible fuel system lines and hoses for escaping smoke. Also check fuel tank sealing cap.
NOTE:
- Illuminate components and hoses with a strong flood light, the smoke will be more visible.
- To check for leaks at accessible locations, also use ultrasonic measuring device or commercially available leak detection spray.
- Depending on how long fault finding lasts, smoke generator button may have to be pressed again. This ensures there is enough smoke present in the fuel system.
If no malfunctions are detected:
- Remove right rear wheel housing liner.
If smoke comes out of air filter :
- Clamp off hose between Evaporative Emission (EVAP) Canister Purge Solenoid Valve 2 N115 and air filter - arrow - . See also .
- Observe air filter. If no smoke comes out of it now, Evaporative Emission (EVAP) Canister Purge Solenoid Valve 2 N115 leaks. Replace Evaporative Emission (EVAP) Canister Purge Solenoid Valve 2 N115 .
If smoke still comes out of air filter:
- Clamp off hose between Leak Detection Pump (LDP) V144 and air filter - arrow - . See also .
- Observe air filter. If no smoke comes out of it now, shut-off valve in Leak Detection Pump (LDP) V144 leaks. Replace Leak Detection Pump (LDP) V144 .
If no smoke comes out of air filter:
- Check all fuel system components and hoses for escaping smoke.
To check fuel pump and fuel filter flange, the assembly opening in vehicle interior must be opened.
- Replace leaking hoses or components.
After completing the work, perform "Check tank ventilation system for leaks" Guided Function using .
Evaporative emissions (EVAP) system, overview
1. EVAP canister
2. Adapter Hose KLI 9210/55-2 installation location
- With leak test in fuel system
3. Evaporative Emission (EVAP) Canister Purge Solenoid Valve N80
4. Vent line
- To Intake manifold
5. Solenoid valve
- For Leak detection pump (LDP) V144
6. Vacuum line
- To Intake manifold
7. Air filter housing
- For Leak detection pump (LDP) V144
8. Leak detection pump (LDP) V144
9. Fuel tank
10. Cap
11. Evaporative Emission (EVAP) Canister Purge Solenoid Valve 2 N115
12. Pressure retention valve
A - Clamp off here
- With leak test in fuel system
- To check Evaporative Emission (EVAP) Canister Purge Regulator Valve N80
B - Clamp off here
- With leak test in fuel system
- To check Evaporative Emission (EVAP) Canister Purge Solenoid Valve 2 N115
C - Clamp off here
- With leak test in fuel system
- To check Leak Detection Pump (LDP) V144
Leak Detection Pump (LDP) V144 pressure buildup, checking
Test conditions:
- Evaporative Emissions Tester KLI 9210 with Adapter Hose KLI 9210/55-2 connected to vehicle
- Valve - D - is at "Hold"
- Diagnostic mode 8 ended and vehicle running at idle
Fuel system must have no pressure for test. To release residual pressure, proceed as follows:
- Briefly open quick-release coupling - arrow - on Adapter Hose KLI 9210/55-2 to release pressure in fuel system. The pressure gauge - D - must drop to 0 in. H(2)O.
- Select Guided Functions operating mode on evaporative emissions tester.
- Select "Check tank ventilation system for leaks" Guided Function.
- Activate test.
- Observe pressure gauge while test is running.
- The Leak Detection Pump (LDP) V144 must pump fuel system up to min. 18 mbar (7 in. H(2)O).
- If pressure is not reached, check Leak Detection Pump (LDP) V144 vacuum supply .
- If fuel system has no leaks and Leak Detection Pump (LDP) V144 vacuum supply is OK, replace Leak Detection Pump (LDP) V144 .
Leak Detection Pump (LDP) V144 vacuum supply, checking
Special tools, testers and auxiliary items required
- Turbocharger tester V.A.G 1397A
- T-piece 251 201 346
- Hose dia. 6 mm
NOTE: Leak Detection Pump (LDP) V144 installation location. Under wheel housing liner in right rear wheel housing.
- Remove right rear wheel and wheel housing liner.
- Loosen EVAP canister mounting bolts and lower it so vacuum line is more easily accessible.
CAUTION: Support EVAP canister so it does not hang by the hoses and lines. This prevents damage.
- Remove vacuum line - 1 - from Leak Detection Pump (LDP) V144 .
- Connect Turbocharger Tester V.A.G 1397A with T-piece and 6 mm dia. hose between vacuum line - 1 - and Leak Detection Pump (LDP) V144 - 2 - .
- Switch on measuring range I (absolute pressure measurement).
- Connect vehicle tester and start engine.
- Select Guided Function operating mode on vehicle diagnostic tester.
- Select "Check tank ventilation system for leaks" Guided Function.
- While test is running, observe display on Turbocharger Tester V.A.G 1397A .
- The pressure must pulsate and must not rise above 0.700 bar during test.
- If pressure rises above 0.700 bar during test, vacuum supply is too low. Check vacuum line to intake manifold for kinks or blockages.