Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information CPM-U300049

Condition
The combustion preheater module (CPM) checks its internal circuits.
The diagnostic trouble code is generated if the control module detects:
- Fault in the control module software.
The control module's test for the diagnostic trouble code (DTC) starts when:
- The control module is activated.

Note! The control module can only detect the fault once the test has been started and the diagnostic trouble code (DTC) is stored when the conditions are met.





Substitute value
- Heater's function blocked.

Possible source
- Software error
- Damaged combustion preheater module (CPM).

Note! If Combustion preheater module (CPM) has software number 30796069 AA, the software is of an older version. For these control modules, the diagnostic trouble code can also be stored if open circuit occurs on the voltage supply or ground connection to the control module when it stores information in their memories.

Fault symptom[s]
- Poor heating in compartment
- Activation parking-/auxiliary heater; no function