On Board Diagnostic (OBD), function

The instrument cluster is controlled by a microprocessor and has extensive On Board Diagnostic (OBD) capability. If malfunctions occur in any of the system components, corresponding DTCs are stored in the Diagnostic Trouble Code (DTC) memory of the instrument cluster.

If OBD recognizes instrument cluster malfunctions related to the:

• odometer
• speedometer calibration

the trip odometer display will change to show "dEF."

In this case, replace speedometer. Refer to Instrument cluster, removing and installing  .

Other malfunctions recognized by OBD will not cause the trip odometer display to change as described above.

Before performing any troubleshooting or inspection, always begin by checking for DTCs using the On Board Diagnostic (OBD) program. DTCs stored in memory are retrieved/checked with VAG 1551/1552 scan tool or VAS 5051/5052 tester in mode "Self Diagnosis". Refer to Instrument cluster On Board Diagnostic (OBD), initiating  .

Where applicable, also use VAS 5051/5052 tester in mode "Guided Fault Finding"

OBD program application notes. Refer to OBD program application notes  .