C1155 is a manufacturer-specific chassis code. Its exact definition depends on the vehicle make, but it typically indicates a left front wheel speed sensor input circuit failure.
Because it is manufacturer-specific, the exact factory definition must be verified before diagnosis. This code identifies a detected fault condition but does not automatically prove the sensor itself has failed.
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Key Takeaways
- C1155 is a manufacturer-specific chassis code that typically points to a left front wheel speed sensor circuit fault on verified applications.
- Possible causes include a damaged sensor, broken wiring, corroded connectors, or a failing ABS control module.
- Diagnosis requires inspecting the left front wheel speed sensor circuit, testing continuity, and verifying the sensor signal.
- Repairs range from repairing damaged wiring to replacing the confirmed failed wheel speed sensor or hub assembly.
C1155 Code Description and Implications
C1155 is a manufacturer-specific diagnostic trouble code. Because it is not a generic SAE code, its exact definition depends entirely on the manufacturer and application.
Some Ford, Mazda, and Lincoln applications: C1155 indicates a Left Front Wheel Speed Sensor Input Circuit Failure. The ABS module detects an open, short, or erratic signal.
Certain Nissan and Jaguar applications: C1155 also points to a left front ABS sensor circuit fault, disabling the anti-lock braking and traction control systems.
Common Causes of the C1155 Code
Because C1155 monitors the electrical circuit for the left front wheel speed sensor, the root cause involves the sensor, wiring, or module.
A failed left front wheel speed sensor or a damaged tone ring can interrupt the speed signal.
Damaged, chafed, or broken wiring in the harness leading to the left front wheel well can cause an open or short circuit.
Corroded, loose, or moisture-intruded electrical connectors at the sensor or the ABS module can disrupt the signal.
Internal ABS control module failure is a possible cause if the sensor and wiring test correctly.
Symptoms Associated With C1155
The most consistent symptom is an illuminated ABS warning light and a disabled anti-lock braking system.
Traction control and stability control systems may also become inoperative, triggering additional dashboard warning lights.
On some applications, the speedometer may behave erratically or stop working if the ABS module provides the vehicle speed data to the instrument cluster.
MIL behavior varies by application. The Check Engine Light may not illuminate, as this is a chassis code, but the ABS and traction control warning lights will typically command on.
Diagnosing the C1155 Trouble Code
Diagnosis must begin by confirming the exact factory definition and service information for the specific make, model, and engine.
Retrieve the code and record any freeze-frame data or related error codes using a scan tool capable of accessing ABS module live data.
Visually inspect the left front wheel speed sensor wiring harness and connectors for damage, chafing, or corrosion.
Use a multimeter to test the sensor resistance and check the wiring for continuity and shorts to ground or voltage.
Monitor the live wheel speed data while driving at a low speed to verify if the left front sensor reads zero or erratic values compared to the other wheels.
Repairing the C1155 Issue
Repairs must follow the confirmed root cause identified during electrical and mechanical testing.
If the wiring harness is damaged or corroded, repair or replace the affected harness section and secure it away from moving suspension components.
If the left front wheel speed sensor fails resistance or signal testing, replace the confirmed failed sensor. On some applications, the sensor is integral to the wheel hub assembly.
If the sensor and wiring test correctly but the ABS module cannot process the signal, the ABS control module may require diagnosis or replacement.
Cost Considerations for C1155 Repairs
Repair costs for C1155 vary based on the underlying fault, vehicle accessibility, and local labor rates.
Repairing damaged wiring involves minimal parts costs and moderate labor time depending on harness routing.
Replacing a wheel speed sensor or a complete wheel hub assembly involves standard parts costs and minimal to moderate labor.
Cost depends on diagnostic time, component accessibility, required parts, programming requirements, and labor.
Prevention Strategies for Future Occurrences
Inspecting the exposed wheel speed sensor wiring for rubbing against suspension components or brake lines can help prevent chafed wires that lead to open circuits.
Keeping the wheel well and sensor connectors clean from excessive road salt and debris may reduce the risk of corrosion and moisture intrusion.
Troubleshooting Tips and Best Practices
Do not assume a C1155 code requires replacing the left front wheel speed sensor immediately; wiring damage near the wheel well is a frequent culprit due to suspension movement.
Always compare the resistance and live data of the left front sensor against the right front sensor to establish a baseline before condemning the component.
Check for applicable technical service bulletins, as manufacturers occasionally release updated wiring harness pigtails or ABS module software recalibrations to address chronic circuit faults.
More OBD-II Codes
| C1100 | C1102 | C1109 | C1111 |
| C1116 | C1143 | C1203 | C1204 |
| C1205 | C1210 | C1211 | C1235 |
| C1237 | C1259 | C1260 | C1282 |
| P0500 | P0501 | P0502 | P0504 |
| P0571 | P0572 | P0573 | P0700 |
Frequently Asked Questions
Is C1155 a generic or manufacturer-specific code?
No. C1155 is a manufacturer-specific chassis code. Its exact definition depends on the vehicle make, though it typically indicates a left front wheel speed sensor circuit fault.
Can a C1155 code cause my ABS and traction control to stop working?
Yes. Because the ABS module relies on wheel speed data, a circuit fault will typically disable the anti-lock braking, traction control, and stability control systems.
Will C1155 clear itself if I fix a wiring issue?
Not automatically. While repairing a broken wire may resolve the underlying cause, the stored code usually requires a scan tool to clear before the monitor can reset.
Is it safe to drive with the C1155 code active?
The vehicle is usually safe to drive to a repair facility, but you will lose ABS and traction control functionality, increasing stopping distances on slippery surfaces.
Does C1155 mean my left front wheel speed sensor is bad?
No. C1155 identifies an electrical fault in the sensor circuit. While the sensor can fail, damaged wiring, corroded connectors, or a tone ring issue must be ruled out.
What Should You Do About the C1155 Code?
Confirm the exact factory definition and technical service bulletins for your specific vehicle application.
Follow the applicable manufacturer diagnostic procedure to test the left front wheel speed sensor circuit, wiring harness, and ABS control module.
Repair or replace the confirmed failed component, then retest the system to ensure the ABS and stability systems operate correctly.
