Pinpoint Test Y : 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.
Normal Operation and Fault Conditions
With the ignition ON, the ABS module sends messages to the SASM over the HS-CAN2. If the SASM does not receive these messages within a certain time frame (usually less than 1 second), the SASM sets Diagnostic Trouble Codes (DTCs). For information on the messages sent to the SASM by the ABS module, refer to the Network Message Chart. Refer to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description .
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| U0121:00 | Lost Communication With Anti-Lock Brake System (ABS) Control Module: No Sub Type Information | This DTC sets in continuous memory and on-demand in the SASM when any of the ABS module messages are missing. This can be due to a ABS module failure, a circuit failure on the HS-CAN or an excessive load on the network. |
Possible Causes
- Wiring, terminals or connectors
- Network communication concern
- ABS module