Reading and Erasing Diagnostic Trouble Codes

This function allows stored diagnostic trouble codes (DTC), counters and frozen values to be read and erased. The diagnostics system can identify 60 different faults in the form of diagnostic trouble codes most of which are followed by a status message. Diagnostic trouble codes can only be erased when all diagnostic trouble code have been read at least once.

When the engine control module detects a fault, the values of certain parameters are frozen and these can be read together with the diagnostic trouble code.

The following frozen values can be read:

- Engine speed.
- Internal load signal.
- Engine coolant temperature.
- Battery voltage.
- Vehicle speed.
- Throttle position sensor status.
- Fuel shut-off system, status.
- Fuel trim, status.
- Operating cycle, status.
- Trip, status.
- Warm-up cycle, status.
- Gear selector, status.
- Flywheel adaption, status.
- Fuel trim, status.
- Pulsed secondary air injection system pump, status.

For further information about frozen values see the section on frozen values under diagnostic trouble codes.