Automatic diagnosis Fiat Marea

The electronic control unit is able to record and save a series of anomalies and faults which could affect the system by means of sensor control software and self-adapting actuators If such anomalies arise, the control unit continues to manage system operation by replacing any anomalous values with recovery values which allow the system to operate at a minimal, albeit not optimal level.

Two types of errors are saved:

  • occasional errors, which are reset when the igntion key is turned to STOP
  • “permanent” errors: if an error occurs more than 5 times in a given time period, it is considered permanent and saved inside the control unit: these errors are NOT reset when key is turned to STOP but only upon a specific external command (Tester).

The control unit allows saved errors to be read in two ways:

  • via a FIAT LANCIA TESTER or other type of tester
  • via the control panel display when enabled to read external temperature.

When a control unit error arises (even if only occasional), the wording “Error Cli” appears on the control panel. This indicates an anomaly. If this wording remains when the “outdoor temperature” key on the middle of the facia is pressed, then the error concerns the outdoor temperature sensor. If the correct temperature value appears, the error relates to other system components. It is the possible to identify the saved anomaly by means of the following procedure:

Automatic diagnosis Fiat Marea

A- set up the following configuration:

  • temperature knob on “HI”
  • distribution knob on “MAX DEF”
  • ventilation knob on “0”

B- turn the key from STOP to MAR

C -within 10 seconds, turn the ventilation knob through the following sequence: “0” – “AUTO” – “0” – “AUTO” – “0”

Now the control unit sends a series of messages to the control panel: one of the error codes shown in the following table is displayed in the place of “CM”.


Reset error codes Fiat Marea


If several errors are present, they are displayed every 3 seconds. The mileometer is displayed again once all the errors have been displayed.

If the system is tested AFTER A REPAIR OPERATION which involved removal of the battery and/or control unit, it is necessary to:

  • turn the key to MAR,
  • wait for about 30 seconds: the control unit runs through its self-adaption cycle
  • return the key to STOP,
  • carry out the test as described.



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