Notes on the BMW Diagnostic System

General

The terminal R (ignition switch in position 1 or 2) must be switched on in order to start the diagnostic procedure. The ignition can, however, be switched off after output of the identification page and the ignition key can be removed from the ignition switch.

Note: In a series of modules, the diagnostic procedure can only be started when the vehicle is unlocked and terminal R is switched on. Also in this case, however, the ignition can be switched off and the vehicle locked after output of the identification page.

Defect Detection

The door lock heating system is constantly monitored for defects by the central locking module II (ZVM). Monitoring takes place via a diagnostic line (diagnostic feedback) which is connected to the ZV module (26-pole connector, Pin 10) and to the load circuit of the door lock heating system.

The following defect status's can be detected:

- Relay of door lock heating system does not pick up.

- Relay of door lock heating system sticking.

- Ground line to heating coil has a break or heating coil defective.

- Activation line from ZV module to relay has a break.

- Diagnostic feedback itself has a break.

The defect code is stored in the defect code memory of the central locking module.

Test Procedure

The door lock contact can be checked by way of *D* test procedure (BMW MoDIC *D* status monitoring)

Door Lock Heating Activation

Activation of the door lock heating system is possible within the user-guided test procedure. However, activation is only possible when:

- The vehicle is unlocked.

- The ignition switch is in position 1 or 2.

Activation in the BMW MoDIC takes place via *D* component activation.

Abbreviations

FH Power window

LB Interior lights

SG Control unit

TSH Door lock heating

ZVM Central locking module

ZV Central locking system