Intake System, Checking For Leaks

Special tools and workshop equipment required

Engine leak detection spray G 001 800 A1

Test requirements

Parking brake must be engaged or else daylight driving lights will be switched on.
For vehicles with automatic transmission, selector lever must be in P.
Coolant temperature must be at least 80° C, Diagnostic mode 1: Check measured values; PID 5, Coolant temperature.

Test sequence

NOTE:

Vacuum in the intake system sucks in the leak detection spray with false air. Leak detection spray decreases ignition quality of the fuel mixture. This causes a drop in engine speed and changes the value produced by the Heated Oxygen Sensor (HO2S).

It is absolutely necessary to follow the safety precautions listed on the can.

-- Connect diagnostic tester.

-- Start engine and let run at idle.

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

-- Select the following measured values:

PID 06: Short time gasoline-air ratio bank 1
PID 08: Short time gasoline-air ratio bank 2
PID 12: Engine rotations per minute (RPM)

-- Observe short time gasoline-air ratio bank 1 and 2 as well as the engine speed.

-- Spray intake system parts with engine leak detection spray in a systematic manner.

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.

Final Procedures

After the repair work, the following work steps must be performed in the following sequence:

Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .