Advanced Diagnostics

Advanced Diagnostics - DTC U1220 (34): DC-DC Converter Lost Communication With Motor Control Module (MCM)






General Description
The DC-DC converter uses an internal timer to measure the intervals between serial communication data updates. When an update is not received for a specified time, a SCIMD serial communication reception malfunction is detected and a DTC is stored.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
The serial communication data is not updated for at least 2 seconds.

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the MCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.