Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSLINCOLN2009NAVIGATOR L RWDREPAIR AND DIAGNOSISENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROLS - POWERTRAIN DTC CHARTS & DESCRIPTIONS (EXCEPT DIESEL & HYBRID)DTC DIAGNOSISDTC U0121: - LOST COMMUNICATION WITH ANTI-LOCK BRAKE SYSTEM (ABS) CONTROL MODULE
2009 Lincoln Navigator L RWD
DTC U0121: - Lost Communication With Anti-Lock Brake System (Abs) Control Module
2009 Lincoln Navigator L RWDSECTION DTC U0121: - Lost Communication With Anti-Lock Brake System (Abs) Control Module
DTC U0121: - LOST COMMUNICATION WITH ANTI-LOCK BRAKE SYSTEM (ABS) CONTROL MODULE
| Description: | The powertrain control module (PCM) continuously monitors the controller area network (CAN) for messages from the ABS. This DTC sets when the PCM fails to receive the ABS message within the defined amount of time. | ||
| Possible Causes: |
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| Diagnostic Aids: | Network DTC concerns occur during module-to-module communication. Refer to the MODULE COMMUNICATIONS NETWORK service information , to diagnose the antilock brake system (ABS) module does not respond to the scan tool symptom. | ||
| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| All | - | ||
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.