Diagnostic Trouble Codes (DTCs)

When a fault occurs it is stored in the control module as a DTC (Diagnostic Trouble Code) provided the car's road speed is over 35 km/h (22 mph) for at least 15 seconds.

The DTCs can be stored in the control module's memory only if the ignition is turned on. When the ignition is switched off these diagnostic trouble codes (DTCs) are erased. For the control module to detect DTCs again the car's road speed must be over 35 km/h (22 mph) for at least 15 seconds.