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 position.
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)

NOTE:

Bank 1 = Cylinder bank 1, in direction of travel, right.

Bank 2 = Cylinder bank 2, in direction of travel, left.

-- Observe the 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.

-- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.

-- Generate readiness code.