Diagnostic Functions

Diagnostic functions

General




The control module has integrated diagnostics, Volvo Diagnostic, which continuously monitors itself and the input and output signals. Any diagnostic trouble codes (DTCs) are stored in the control module. Diagnostic trouble codes (DTCs) can be read off later. The principle for presentation of information is the same as for other diagnostic systems.

Fault indication
If any faults occur in the tow hitch system the driver is warned via the Driver information module (DIM), by the information lamp lighting up and a warning message being displayed.
A VIDA station must be connected to the data link connector (DLC) in order to identify the source of the fault.

Diagnostic trouble codes (DTCs)
A diagnostic trouble code (DTC) is stored if the control module detects a fault.
Diagnostic trouble codes (DTCs) for different types of short circuits are only stored when no trailer connector is connected to the output. This is so that Diagnostic trouble codes (DTCs) are not stored when there are faults in the trailer's cable harness or connectors.
Should a fault disappear for any reason after being stored in the control module as a diagnostic trouble code (DTC), the information remains stored in the control module. If a fault is no longer permanent, the diagnostic trouble codes (DTCs) remain as intermittent.

Reading and erasing diagnostic trouble codes (DTCs)
Stored diagnostic trouble codes (DTCs) can be read off and erased using this function.
This function can also be used to read off whether the fault is still present (permanent) or whether it has now ceased (intermittent) after the diagnostic trouble code (DTC) has been stored.
Diagnostic trouble codes (DTCs) can only be erased once all the diagnostic trouble codes (DTCs) have been read off at least once.

Reading off the parameters
Data can be read off from the Trailer module (TRM) using this function.
Battery voltage
Reads off the level of the power supply to the control module.
Input signal
Reads off the status of the directly connected stop lamp signal from the central electronic module (CEM).
Output signals
Reads off the status of the output signals to the cable harness for the tow hitch.
Trailer connector
Reads off if the trailer connector is connected to the output on the cable harness for the tow hitch.

Reading off control module identification
The control module can be identified by reading off a number of codes from the control module memory. The codes contain information about the control module:
- hardware P/N (control module without software)
- hardware serial number (control module without software)
- software P/N
- software number, diagnostics.