Test Point 1 - Checking Ground and Plug Connections
TEST POINT 1 - DME 944 TurboNote: The test points should be performed in the specified sequence, especially when the cause of detect is apparently no or poor engine running.
Test point 1 is especially important!
Check ground plug connections.
A) Ground Points (V)
On clutch bell housing and engine flange (underneath plug connections of reference mark and speed sensors).
Ground wire from body to engine.
Are ground connection points clean and tight?
Note: Never start the engine when the body/engine ground wire is disconnected!
This would destroy the control unit immediately.
B) Plug Connections
14-pin plug connection in engine compartment above the brake booster.
On cyl. no.4 intake pipe.
Reference mark, speed and oxygen sensor plug connections.
On idle positioner - 3-pin plug connection.
On throttle valve potentiometer - 6- pin plug connection.
On DME control unit - 35-pin plug connection - and on knock/charging pressure control unit - 25-pin plug connection (behind front passenger's foot support).
NTC II in engine block above left balancing shaft - 2-pin plug connection.
On air flow sensor - 4-pin plug connection.
On timing valve between intake pipes 3 and 4 - 2-pin plug connection.
On knock sensor/engine block between cylinders 2 and 3 - 2-pin plug connection.
Finally the 4 plugs for fuel injectors - each 2-pin.
Are plugs connected correctly, not corroded and with tight plug contacts?