Using BMW MoDIC Or BMW Service Tester

Use BMW MoDIC (hand-held scan tester), BMW Service Tester (Sun 2013 Engine Analyzer) and applicable BMW diagnostic software to enter self-diagnostics and retrieve 2-digit codes. See SELF-DIAGNOSTICS FEATURE and CLEAR DEFECT CODE MEMORY FUNCTION for additional information.

NOTE: When DME/Motronic control unit is disconnected or its power supply interrupted, all stored (hard) fault codes as well as substitute values are cleared/lost. Current (intermittent) fault codes cannot be cleared.

Communication with the control unit via the diagnostic system can be set up after selecting the DME on the BMW service tester. If data transfer is interrupted, information appears on the display screen indicating the possible causes:

Ignition not switched on.
Voltage supply for control unit less than 10 volts.
DME relay not supplied with battery voltage (if not: bypass terminal 30 and 87).
Control unit not connected.
Diagnostic link defective.
Data traffic inhibited by a defective control unit in the vehicle.

The first step should always be to monitor the defect code memory. If one or several defect codes are stored, it is advisable to immediately print out data. Since it is often necessary during the testing procedure to cut the power supply or to disconnect the connector from the control unit, the contents of the defect code memory will be unintentionally deleted as a consequence.

The memory stores the defect codes in the order they occurred. With the exception of code 200, defect codes are stored only when the engine is running. Substitute values can be active when a defect code is stored and the DME is not malfunctioning. The troubleshooting procedure should still, however, be carried out.

The learned adaption values are lost if the battery or DME control unit is disconnected. This may result in difficulties in starting and idling. Defects which influence the mixture are indicated by a CHECK ENGINE light in the instrument cluster. As a check, this light comes on constantly during the period of time between ignition ON and engine start.