Description of On-Board Diagnostic System

Notes on the BMW DIAGNOSTIC SYSTEM:

*D* Test Procedure:

The inputs of the EKM can be checked with the test procedure. The screen pages contain detailed information on the operation and troubleshooting of the connected switches and sensors.

The check control displays are shown irrespective of whether a message is output in the MID. An additional condition is frequently necessary for output of a message.

Example:

The message "door open" is not output when the vehicle is moving. The message "wash water" is only indicated when the ignition is switched off or on.

*D* Activating Components:

The outputs of the EKM can be checked by way of activation.

A frequency or a speed can be preset for checking the speed signal. Observe information on screen pages.

*D* Defect Code Memory:

The EKM can detect a large number of defects. However; it can not differentiate whether a defect has occurred once or several times, or whether the defect is a current defect.

Therefore, before starting extensive tests, determine by way of checking the function or with the *D* test procedure whether the indicated defect is a current in the vehicle.

The defect code is not cleared by disconnecting the battery or removing the EKM.

*D* Special Functions - System Test:

The EKM system test makes it possible to check the inputs. The frequency inputs (tD, ti, position signal), the data link to the instrument cluster as well as the analogue inputs (temperature sensor etc.) are not checked.

All 26-pole connectors must be disconnected from the EKM in order to perform the test. The 5-pole connector must remain connected.

After the test has started, the EKM automatically switches all inputs on and off and checks by way of diagnostic feedback whether the switching procedures are performed correctly.

Defective inputs are indicated on the display screen.

Troubleshooting:

Notes:

- Troubleshooting is mainly performed in accordance with information provided in the BMW DIAGNOSTIC SYSTEM. Observe notes shown on the display screen.