C1168 — Speed Wheel Sensor RR Coherency Fault #

Note: The wording for this code may differ depending on the vehicle manufacturer (OEM). Below are some known variations:

• Speed Wheel Sensor Rear Right Coherency Fault (Nissan, Renault, Ford)
• Right Rear Wheel Speed Sensor Signal Incoherence (Mazda)
• RR Wheel Speed Sensor Correlation Error (Infiniti)
• Rear Right Wheel Sensor Implausible Signal (Peugeot, Citroën)

Summary of the C1168 Code #

C1168 is a diagnostic trouble code (DTC) indicating that the Right Rear (RR) Wheel Speed Sensor is sending data that does not align with expected values, as determined by the vehicle’s Anti-lock Braking System (ABS) module. The term “coherency fault” means the sensor’s output is inconsistent compared to the other wheel speed sensors. The ABS system relies on accurate information from each wheel to ensure proper braking and stability control. If one sensor (in this case, the right rear) provides a signal that deviates too much from the others, the system logs this fault. This code can affect ABS, traction control, and sometimes stability systems, making prompt attention important for safe vehicle operation.

Common Symptoms for Code C1168 #

When your vehicle stores a C1168 code, you may notice changes in how it behaves, especially under braking or in slippery conditions. The most frequent symptoms are:

• ABS warning light illuminated on the dashboard
• Traction control or stability control light may also come on
• Loss of ABS function (wheels may lock during hard braking)
• Possible loss of traction or stability control assistance
• Unusual braking behavior, such as pulsing or uneven stopping

Likely Causes of C1168 (Most to Least Common) #

The C1168 code is usually triggered by issues with the sensor or its circuit, but can also result from more complex problems in rare cases. Here’s what most often causes this fault:

1. Faulty right rear wheel speed sensor (the sensor itself is defective)
2. Damaged or corroded wiring/connectors between the sensor and the ABS module
3. Broken or contaminated tone ring (the toothed ring that the sensor reads)
4. Wheel bearing issues causing excessive sensor gap or misalignment
5. ABS module malfunction (rare, but possible)
6. Incorrectly installed or mismatched tires (inconsistent rolling radius)

Step-by-Step Diagnosis for Code C1168 #

Diagnosing a C1168 code requires a logical, methodical approach to rule out simple issues before considering more complex ones. Here’s how a technician or knowledgeable DIYer should proceed:

• 1. Scan all related codes. Note if other ABS or wheel speed sensor codes are present.
• 2. Visually inspect the right rear wheel speed sensor and wiring. Look for frayed wires, loose connectors, or corrosion.
• 3. Check for physical damage or contamination on the sensor and the tone ring. Clean any dirt or debris.
• 4. Measure sensor output with a multimeter or scan tool while rotating the wheel. Compare to the readings from other wheels.
• 5. Examine wheel bearing and hub for play or misalignment that could affect sensor gap.
• 6. Inspect tire size and condition on all wheels to ensure uniformity.
• 7. If all else checks out, test ABS module function (advanced step; may require OEM scan tool).

Possible Repairs for C1168 #

Repairing a C1168 code depends on which cause is identified during diagnosis. Address the root cause directly:

• Replace the right rear wheel speed sensor if it’s faulty or damaged
• Repair or replace damaged wiring/connectors to the sensor
• Clean or replace the tone ring if contaminated or broken
• Replace worn or faulty wheel bearing/hub assembly if needed
• Reprogram or replace the ABS module only if confirmed defective
• Install correct, matching tires on all wheels if mismatched tires are found

Is It Safe to Drive with Code C1168? #

Limited — Caution Advised: While your vehicle may still be operable, driving with a C1168 code means your ABS and possibly traction/stability control systems are compromised. In emergency braking or slippery conditions, you may lose critical safety features, increasing your risk of an accident. It’s best to address this issue as soon as possible and avoid driving in hazardous conditions until repaired.

Vehicles Most Commonly Affected by Code C1168 #

While C1168 can appear on many vehicles equipped with ABS, it is most frequently seen on models from the following manufacturers:

• Nissan (Altima, Maxima, Rogue, Murano, Pathfinder)
• Infiniti (G35, QX60, FX35)
• Renault (Laguna, Megane, Scenic)
• Mazda (6, CX-5, CX-9)
• Ford (Transit, Focus, Mondeo, Galaxy)
• Peugeot/Citroën (308, 3008, C4, C5)

Common Pitfalls & Best Practices for C1168 #

Mistakes in diagnosing or fixing C1168 can lead to wasted time or money. Here’s how to avoid common errors:

• Don’t replace the sensor before checking the wiring — wiring faults are common and easy to overlook.
• Avoid ignoring tire mismatches — differences in tire size or wear can cause false sensor readings.
• Don’t clear the code without fixing the cause — the warning will return, and safety remains compromised.
• Always compare sensor readings side-to-side with a scan tool to spot anomalies.
• Use only high-quality or OEM parts — cheap sensors may introduce new faults or signal errors.

Quick FAQ for C1168 #

What does “coherency fault” mean for my wheel speed sensor?
A “coherency fault” means the right rear wheel speed sensor is sending signals that don’t match or “align” with the data from the other wheel sensors, suggesting a possible malfunction or data error.

Will replacing only the sensor fix C1168?
Often, but not always. While the sensor itself is a common failure, wiring problems, tone ring issues, or even tire mismatches can also trigger the code. Always diagnose carefully before replacing parts.