Diagnostic Trouble Code Detection

If the control module detects a fault it is stored as a diagnostic trouble code (DTC). In all 23 diagnostic trouble codes (DTCs) can be detected and stored. See DTC table. page 22. The control module can store up to 8 diagnostic trouble codes (DTCs) at any one time.

When a diagnostic trouble code (DTC) is stored, values for a number of pre-determined parameters are frozen. The frozen values can be used to read out, for example, what the control module has registered regarding the position of the control buttons or the value from a potentiometer when the fault occurred.

For each diagnostic trouble code (DTC) there is a counter, counter 2, which provides the total number of cycles completed without a fault since the diagnostic trouble code (DTC) was stored.

A cycle begins every time one of the buttons on the control panel is pressed. Where a counter counts when a button is pressed there is no fault at that particular moment in time. This function can be used to determine if a fault is permanent or intermittent.

After all diagnostic trouble codes (DTCs) have been read off and the necessary repairs made they must be erased. The seat can then be tested, following which a new reading of diagnostic trouble codes (DTCs) should be made to verify that the fault has been corrected.

One diagnostic trouble code (DTC) PSL/PSR-424 is, however, permanent and cannot be erased.