Pinpoint Test G : U0121:00: Notes
WARNING: This page is about a different car, the 2018 Ford F-550 Super Duty, 2018 Ford F-450 Super Duty, 2018 Ford F-350 Super Duty, and 2018 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
Refer to MODULE COMMUNICATIONS NETWORK for schematic and connector information.
Normal Operation and Fault Conditions
The TCM sets the DTC U0121 when key messages such as wheel speed, brake pressure or torque are not received for longer than 5 seconds. Other modules that require data from the ABS module all set communication DTCs and may also exhibit system concerns.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| U0121:00 | Lost Communication with ABS module: No Sub Type Information | Sets in continuous memory in the TCM if ABS data messages received from the ABS Module over the HS-CAN are missing for longer than 2 seconds. |
Possible Sources
- Communication concern
- Battery voltage concern
- GWM concern
- TCM
- ABS