EVAP Emissions System Diagnosis Using KL 19210 EVAP Tester

Evaporative Emissions (EVAP) System Diagnosis using KL19210 EVAP Tester
Description
The leak detection threshold has recently changed from 1.0 mm (0.040 inch) to 0.5 mm (0.020 inch). These changes to EPA regulations regarding EVAP system integrity indicated that additional resources for more accurate EVAP system diagnosis are necessary.
The KL19210 EVAP Tester allows testing using nitrogen to pressurize the EVAP system and a smoke generator or ultrasonic tester to locate the source of EVAP system concerns.
The following procedure will outline general use of the KL1921. EVAP Tester. It is intended as a guideline, as EVAP systems vary between models.

Test EVAP system using Leak Detection Pump (LDP) 4144- (m.y. 1998 and later)
For vehicles without LDP, proceed to "Perform EVAP tester self-test".
For vehicles with LDP:
- Perform leak test using VAS 5051 Scan Tool and Basic Setting mode.
If vehicle fails above test ("System not OK"):
- Verify fuel cap is properly closed; repeat test.
If "System OK" after re-test-.
- Erase DTC memory (if necessary).
- Repeat test several times to ensure proper EVAP system operation (remove and re-install fuel cap before each test).
- Perform quality check and return vehicle to customer.

Note: If the vehicle passes the above EVAP system test, DTC's may be sporadic; the entire EVAP system should be carefully inspected.
If VAS 5051 continues to indicate "System not OK" after re-test, proceed to next step.

Perform EVAP tester self-test

Note:
^ Always perform system self-test of KL192 10 EVAP Tester prior to use to ensure that there are no leaks.
^ Refer to KL192 10 instruction manual for specific instructions.





-Connect vehicle interface hose to self-test port -1 ensuring that fitting is finger-tight. Over-tightening will damage fitting.
- Turn control valve -2- to "Test".
Gauge -3- should read 14 ± 1 in. of water.
If gauge does not read 14 ± 1 in. of water
- Verify that valve on EVAP tester nitrogen cylinder is open and that cylinder has sufficient pressure before continuing.





- Turn fine adjust regulator knob (arrow) until gauge reads 14 in. of water; tighten lock nut.

Note: If gauge still does not read within above range, contact K-Line Customer Service - Technical Support for additional instructions before continuing.

- Check flow meter -4-. (upper illustration).
Meter must indicate no flow.
- Turn control valve to "Hold" position.
- Check gauge.
Gauge must hold pressure

If gauge leaks down-.
- Verify that vehicle interface hose is firmly seated and repeat previous six steps before continuing.
If gauge continues to leak down-.
- Use ultrasonic tester (described later) to locate and repair leak before continuing.

Note: If the leak cannot be located or repaired, contact K-Line Customer Service - Technical Support.

Calibrate KL19210 Tester
Determine vehicle leak threshold-.
To m.y. 2000- leak threshold 0.040 in.
From m.y. 2001. leak threshold 0.020 in.





- Attach test hose to appropriate preset port (black arrows).
- Turn control valve from "Hold" to "Test".
- Set flow meter flag (white arrow) at indicated value on flow meter.
- Turn control valve to "Hold"; remove test hose.

Test fuel cap
- Connect fuel cap tester to hose.





- Screw fuel cap tightly to cap receiver (arrow).
- Turn control valve to "Test".
- Read flow meter on tester.
If no flow is indicated-.
- Proceed to "Test LDP for internal leaks".
If flow is indicated
- Replace fuel cap and re-test.
If new fuel cap shows no flow:
- Repeat Leak Test, with new fuel cap installed, using VAS 5051 and Basic Settings mode.
If Leak Test shows "System OK"-.
- Perform quality check and return vehicle to customer.

Test LDP -V144- for internal leaks
If vehicle is not LDP-equipped, proceed to "Test EVAP system".
- Clamp off LDP outlet (EVAP side) using Special Tool No. 3094 or equivalent.

CAUTION: Clamp only soft rubber lines when isolating a leak. To avoid risk of damage, never clamp hard plastic lines!

- Repeat Leak Test using VAS 5051 and Basic Setting mode.
VAS 5051 should immediately indicate "System 0K11
- Repeat test several times to verify result.
If test continues to indicate "System OK", remove clamp and proceed to "Test EVAP System".

If VAS 5051 indicates "System not OK":
- Replace LDP and repeat test.
If VAS 5051 indicates "System OK" after LDP is replaced and test result is verified:
- Perform quality check and return vehicle to customer.

Test EVAP System
If vehicle is not LDP-equipped:
- Plug or clamp EVAP canister outlet and proceed to step "Continued for all vehicles" (below).
If vehicle is LDP-equipped:
- Plug or clamp LDP inlet (filter side) using Special Tool No. 3094 or equivalent.





- Attach fuel cap adapter to filler neck (arrow) and test hose to adapter.
- Turn control valve from "Hold" to "Test".
- Allow fuel system to pressurize.

Note: Fuel system pressurization depends on volume of fuel system and amount of fuel in tank.
If fuel system pressurization does not stabilize-.

- Verify all fuel system outlets have been sealed before continuing.

CAUTION: Clamp only soft rubber lines when isolating a leak. To avoid risk of damage, never clamp hard plastic lines!

Note: Any flow shown on flow meter indicates a leak. Flow before flow meter flag set at vehicle leak standard may indicate a sporadic DTC.

If flow meter on tester registers flow near or above preset pressure-.





- Clamp off hose (arrow) leading from EVAP purge regulator valve -N80-to intake manifold (pictured AHA engine in A6).
If flow stops..
- Replace EVAP purge regulator valve -N80- and repeat test before continuing.
If meter indicates no flow after test:
- Perform a quality check and return vehicle to customer.
If flow continues, proceed as follows:

Method 1: Locate leak with smoke generator
- Connect leads from smoke generator to vehicle battery.
- Use smoke generator trigger to charge fuel system with smoke.
- Inspect complete EVAP system for escaping smoke.





Method 2: Locate leak with ultrasonic tester
General search- tester only
Localized search- tester with extension (on left in illustration)
If leak cannot be located
- Disconnect and plug or clamp shut EVAP lines to isolate fuel tank, using Special Tool No. 3094 or equivalent, before continuing.

CAUTION: Clamp only soft rubber lines when isolating a leak. To avoid risk of damage, never clamp hard plastic lines!

If flow stops..
- Reconnect EVAP lines to search area that was isolated
If leak or source of fuel odor cannot be found
- Contact Technician Helpline.

CAUTION: Under no circumstances should the vehicle be returned to the customer without proper diagnosis and repair.

When leak has been located
- Repair leak and repeat EVAP system test.
- Perform quality check and return vehicle to customer.

Note:
^ Because leak may be at top of fuel tank, it may not be possible to locate through fuel pump sending unit access plate.
^ Fuel tank may need to be lowered to locate the leak.