Fuel Delivery and Air Induction: Testing and Inspection

Intake System, Checking For Leaks (False Air)

Checking with engine leak detection spray

Recommended special tools and equipment
- Engine leak detection spray G 001 800 A1

Test requirement
- Coolant temperature must be at least 80 degrees C. Diagnostic mode 1: Check measured values; PID 5, Coolant temperature. Diagnostic Mode 1: Check Measuring Values

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. Diagnostic Tester, Connecting
- 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
- PID 08: Short time gasoline-air ratio bank 2
- PID 12: Engine rotations per minute
- Observe the short time gasoline-air ratio as well as engine speed.

NOTE:
- Bank 1 = Cylinder bank 1, in direction of travel, right.
- Bank 2 = Cylinder bank 2, in direction of travel, left.


- 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. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes