Diagnostic Mode 08 - Request Control of On-Board System, Test or Component
Diagnostic Mode 08 is used to control the operation of an on-board system, test or component. A Mode 8 service can be used to turn on-board system ON or OFF, or to cycle an on-board system, test or component ON or OFF for a specific period of time. The service can also be used to request system status or to report test results.
Diagnostic Mode 08, TID $01
Diagnostic Mode 08, TID $01 is used to determine if the evaporative system may be leaking.
NOTE:
- Evaporative Emission (EVAP) Canister Purge Regulator Valve 2 N333 and fuel system Leak Detection Pump (LDP) V144 seal fuel system.
- Using engine leak detection spray (e.g.: G 001 800 A1) leaks can be detected.
Test Conditions
- There must not be any DTCs stored in DTC memory Diagnostic Mode 03 - Read DTC Memory , Diagnostic mode 3: Check DTC memory.
- Coolant temperature must be 80 to 110 degree C Diagnostic Mode 01 - Read Current System Data , Diagnostic mode 1: Check measured values; PID 05, Coolant temperature.
- Intake air temperature must not be above the maximum of 60 degree C Diagnostic Mode 01 - Read Current System Data , Diagnostic mode 1: Check measured values; PID 15, Intake air temperature.
Function Test
- Connect diagnostic tester.
- 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: | Specification: |
|---|---|
| Is being initiated, please wait Aborted Active Off | Test function active |
NOTE:
- During tank leak test, "test function active" is limited 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 diagnosis and switch ignition off.
If a leak is detected:
- EVAP canister system, checking for proper seal →
- Evaporative Emission (EVAP) Canister Purge Regulator Valve 2 N333 , checking → EVAP Canister Purge Regulator Valve 2, Checking .
- Fuel system Leak Detection Pump (LDP) V144 , checking.
- Erase DTC memory of Engine Control Module → Diagnostic Mode 04 - Erase DTC Memory , Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness codeReadiness code .