Body control unit (Diagnostic socket): Description and operation

Diagnostic socket

RHD illustrated

The BCU has a serial connection to the diagnostic socket to allow unit interrogation using TestBook.

In addition to fault diagnosis, the BCU can be programmed with the following information: l Plip codes. l Options. l VIN code. l EKA code. l EEPROM locking.

The following manufacturing details are programmed into the BCU which can be accessed using TestBook: l Date of manufacture. l Hardware version number. l Unit serial number. l Odometer reading.

It is not possible to use the diagnostic bus to communicate with the BCU via TestBook when the security system is active (except for passive immobilisation). This is a security measure to ensure that no key programming or market configuration can take place if the operator is not in possession of a valid remote transmitter or the vehicle keys.

The BCU is normally programmed to accept two remote transmitters, but a further two remote handsets can be programmed into the BCU and one optional Self Levelling Suspension (SLS) transmitter. All remote transmitters need to be available if TestBook is to be used to re-configure the BCU.