With Generic Scan Tool
Intake system for leaks (unmetered air), checking
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°C, Diagnostic mode 1: Check measuring values; PID 5, Coolant temperature. Diagnostic Mode 1: Check Measuring Values
Test sequence
NOTE:
- The negative pressure in the intake system sucks in the leak detection spray with the unmetered air. Leak detection spray decreases ignition quality and performance 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: Checking measuring values."
- Select the following measuring values and check the specified values at idle:
Vehicles with engine code AHA
Vehicles with engine code ATQ
Continuation for all vehicles
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 eliminate the malfunction.
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes