Checking the resistance

Checking the resistance

The resistance of the solenoid valve can be measured by disconnecting the connector and connecting an ohmmeter as illustrated in the diagram.

Resistance: 17.5-23.5 ohm at 20 °C

Wiring connector

The numbers indicate the corresponding control unit pins

CHECKS - ADJUSTMENTS AND REPAIR OPERATIONS ON THE BOSCH MOTRONIC ME 3.1 INJECTION/IGNITION SYSTEM IN ADDITION TO THE FAULT DIAGNOSIS

WHEN WORKING ON A VEHICLE EQUIPPED WITH A MOTRONIC INJECTION/IGNITION SYSTEM, OBSERVE THE FOLLOWING PRECAUTIONS:

• do not start up the engine with the terminals for the electrical connections not properly connected or slack at the battery poles;
• do not use a rapid battery charger to start the engine;
• never disconnect the battery from the on board system with the engine running;
• when recharging the battery, disconnect it first from the system;
• if the vehicle goes into a drying oven after painting, at temperatures in excess of 80 °C, then the injection/ignition electronic control unit must be removed first;
• never connect or disconnect the electronic control unit multiple connector with the ignition switch in the ON position;
• always disconnect the negative battery lead before carrying out electrical welding on the vehicle.

It should be remembered that this system has a memory which is always supplied (stand-by memory) which contains all the self-adjustment figures. If the battery is disconnected then this information is lost and can only be acquired again after a certain length of time so this operation should be carried out as infrequently as possible.

If the engine control unit or the motorized butterfly casing is being replaced, the self-learning procedure must be carried out for the return spring inside the butterfly casing and maximum/minimum motorized butterfly valve angular positions.