Lost Communication With VSA Modulator-Control Unit

DTC U0122: Lost Communication with VSA Modulator-Control Unit




General Description
The controller area network (CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using two signal lines (CANH and CANL).

When the powertrain control module (PCM) does not receive the signals via the CAN lines for more than a set time, the PC detects a malfunction and a DTC is stored.




Monitor Execution Sequence, Duration, DTC Type, OBD Status




Enable Conditions

Malfunction Threshold
No signals from the VSA modulator-control unit via the CAN lines are received for at least 1 second.

Diagnosis Details

Conditions for illuminating the indicator
When a malfunction is detected, the D indicator blinks, and the DTC and the freeze frame data are stored in the PCM memory. The MIL does not come on.

Conditions for clearing the DTC
The DTC and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.