DTC | Description | Action |
|---|---|---|
All Other DTCs | — | Refer to Powertrain Control/Emissions Diagnosis (PC/ED) manual. Section 3 Symptom Charts. |
Pinpoint Tests
U0121
DTC Fault Trigger Condition-PCM
DTC | Description | Fault Trigger Conditions |
|---|---|---|
U0121 Lost Communication With Anti-Lock Brake System (ABS) Control Module | The PCM sets this DTC if data messages received from the ABS module over the High Speed Controller Area Network (HS-CAN) are missing. |
Normal Operation and Fault Conditions
REFER to: Communications Network - System Operation and Component Description (418-00 Module Communications Network, Description and Operation).
Possible Sources
ABS module BCM PCM
PINPOINT TEST A : U0121
A1 VERIFY THE CUSTOMER CONCERN
Ignition ON. Verify there is an observable symptom present.
Is an observable symptom present?
Yes | GO to A2 |
|---|---|
No | The system is operating normally at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. |
A2 CHECK THE COMMUNICATION NETWORK
Using a diagnostic scan tool, perform a network test.
Does the ABS module pass the network test?
Yes | GO to A3 |
|---|---|
No | REFER to: Communications Network (418-00 Module Communications Network, Diagnosis and Testing). |
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.