Test Point 13 - Leaks In Intake System

TEST POINT 13 - DME 944

Leaks in Intake System




Check all connections after air flow sensor for tightness and leaks.
Build up 0.5 bar pressure in intake system with locally made tool and check for leaks.


Checking Function of Altitude Correction Box (only USA Engines and M 298/M 299)
(for testing below 1000 meters above sea level)


Altitude correction box is located near the DME control unit.

1. Engine idle speed, disconnect oxygen sensor plug, check CO in front of catalytic converter.
2. Disconnect altitude correction box plug.
3. Bridge plug connections with a piece of suitable wire.
4. CO should lean by approx. 1 % (at idle speed).
5. Connect ohmmeter on altitude correction box wire plug. Ohmmeter should display infinite ohm (switch open).
Display: approx. 0 - 10 ohm from about 1000 meters above sea level on (switch closed).