Diagnostic mode 8: Tank leak test
Function
This diagnostic mode checks the fuel system for leaks.
NOTE:
- The Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80- and Leak Detection Pump (LDP) -V144- seal the tank system.
- Using engine leak detection spray (e.g.: G 001 800 A1) leaks can be detected.
Requirements
- There must not be any DTCs stored in DTC memory. Refer to Diagnostic mode 3: Check DTC Memory .
- Coolant temperature must be 80 to 110° C. Refer to Diagnostic mode 1: Check measured values
- Intake air temperature must not be above the maximum of 60° C. Refer to Diagnostic mode 1: Check measured values
Checking function
- Connect diagnostic tester. Refer to Diagnostic tester, connecting
- Start engine and let run at idle for at least 15 minutes.
- Under address word 33, select "Diagnostic mode 8: Tank leak test".
- Select measuring value "Test-ID 01: Tank leak test".
- Check specified value of tank leak test at idle.
Evaluation test-ID 01: Tank leak test
| Test function: | Specified value: | |||||
|
Test function active | |||||
NOTE:
- During tank leak test, Engine Control Module (ECM) limits "test function active" to approx. 12 minutes.
- If the accelerator pedal is depressed during the test, the test will be aborted.
- To repeat the tank leak test, switch ignition off and start engine again and let run at idle for at least 15 minutes.
- End diagnostic and switch ignition off.
If a leak is detected:
- Check EVAP canister system for proper seal. Refer to EVAP canister system, checking for proper seal .
- Check Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-. Refer to Evaporative Emission (EVAP) canister purge regulator valve, checking .
- Check Leak Detection Pump (LDP) -V144-. Refer to Leak Detection Pump (LDP), checking .
- Erase DTC memory of Engine Control Module (ECM). Refer to Diagnostic mode 4: Reset/erase diagnostic data
- Generate readiness code. Refer to Readiness code, generating