What does C1234 mean on a Ford?

C1234. Right Front Wheel Speed Input Signal Missing. Applies to Focus, F-150, Explorer, Ranger.

What causes C1234 on a Ford?

Dead right front wheel speed sensor Severed RF sensor wire Missing tone ring teeth Sensor backed out of its mount ABS module input fault

How do I fix C1234 on a Ford?

Confirm zero RF speed while others read on a roll test Inspect the sensor mount and air gap Check wiring continuity end to end Examine the tone ring Replace the sensor per findings

Code

C1234

Right Front Wheel Speed Input Signal Missing

Category: Chassis
Severity: ABS Light
Applies to: Focus, F-150, Explorer, Ranger
Related: No single generic twin. See OBD Codes List

Findings, check these first

Dead right front wheel speed sensor
Severed RF sensor wire
Missing tone ring teeth
Sensor backed out of its mount
ABS module input fault

Standard procedure

Confirm zero RF speed while others read on a roll test
Inspect the sensor mount and air gap
Check wiring continuity end to end
Examine the tone ring
Replace the sensor per findings

Code lookup

Type a code above, or start from a symptom or a common code.

Press / to jump to the box. Ford-enhanced powertrain, body, chassis and network codes. Generic P0xxx codes live on OBD Codes List.

Sources and review

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Last updated 2026-09-25.

Report a correction for C1234. Include your vehicle, the issue and a source if you have one.

This fault is part of the Ford ABS and traction control codes guide. It covers the family and the order to check it.