Intake System, Checking For Leaks

Diagnostic Procedures




Intake System, Checking for Leaks

Checking With Engine Leak Detection Spray

Special tools, testers and auxiliary items required

• Engine leak detection spray G 001 800 A1

Test conditions

• Parking brake must be engaged.

• For vehicles with automatic transmission, selector lever must be in " P".

• Coolant temperature must be at least 80 °C => [ Diagnostic Mode 01 - Read Current System Data ] Diagnostic Modes 01 - 09, Diagnostic mode 1: Check measured values; PID 5, Coolant temperature.

Test sequence

• The negative pressure in the intake system sucks in the leak detection spray with the false air. Leak detection spray decreases ignition quality of the fuel mixture. This leads to a decrease in engine speed and a change in oxygen sensor values.

• The safety precautions listed on the can must be observed.

- Connect diagnostic tester.

- Start engine and let run at idle.

- Under address word 33, select "Diagnostic mode 1: Check measured values".

- Select the following measured values:

• PID 06: Short time gasoline-air ratio bank 1/3

• PID 08: Short time gasoline-air ratio bank 2/4

• PID 12: Engine rotations per minute (RPM)

• Bank 1 and 2 = exhaust bank 1 and 2 (with module number "10 - Engine electronics").

• Bank 3 and 4 = exhaust bank 3 and 4 (with module number "11 - Engine electronics II").

- Observe short-term gasoline-air ratio as well as engine speed.

- Systematically spray components of intake system with engine leak detection spray.

If engine speed drops or if the short-term gasoline-air ratio changes:

- End diagnosis and switch ignition off.

- Check sprayed part of intake system for leaks, and repair the malfunction.

- Erase DTC memory of Engine Control Module => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code => [ Readiness Code, Generating ] Monitors, Trips, Drive Cycles and Readiness Codes.