Diagnostic Bus System
The Diagnostic Bus System is made up of two separate bus-systems which allow the DISplus to communicate with the vehicle control units via the diagnostic socket
- The Diagnostic bus (ISO 9141-2 OBD II): This allows communication with the DISplus and power train (emission) related control units
- The DS2 Protocol bus: This connects to the control units that do not affect emissions and to the instrument cluster (IKE), which enables communication with all the control units on the K-bus system
The Diagnostic bus uses a single wire transmitting at 9,600 bits a second. The diagnostic line is used by DISplus to interrogate each control unit on the network and helps in the fault finding process. It uses a protocol very similar to that of the K-bus system and is accessed by DISplus via the 16 pin diagnostic connector located in the driver's footwell (under the dash, close to the A post).
Scheme 1
Oil Service and Inspection
The remaining distance shows the distance until the next service, which may be of either an oil service or inspection type. Whenever the SIA information is displayed the type of service next required is also displayed using either the 'oil service' or 'inspection' icons. The type of service next required alternates between oil service and inspection. When either an oil service or inspection is due the remaining distance figure will flash. If either of the oil or inspection services is overdue by a remaining distance greater than the recommended distance then both the 'oil service' and 'inspection' icons are displayed.
IKE Test Functions
In addition to the fault memory and diagnostic link, the base instrument cluster contains a series of test functions that can be accessed to check various functions and values. The test functions are displayed in the mileage LCD block. There are a total of 21 test functions.
The test functions are similar to those of previous Board computers and contain similar tests.
Scheme 2
Scheme 3
Scheme 4
Scheme 5
Scheme 6
Scheme 7
- Tests 1 & 2 are always unlocked.
- Tests 3 -21 are only accessible after unlocking the test function. Test 19 is the unlock function for accessing the displays.
Diagnostics
The RDW features full diagnostic capabilities. Diagnosis indicates how often and at what speed a fault has occurred. It also indicates whether initialization has taken place or not.
Diagnosis
Faults, which are determined, are filed in the fault memory and may be read out by means of the DISplus. The fault memory is formed by means of the EEPROM of the microprocessor so that the filed data is also maintained when the system is in an inactive status.