C1110 — ABS Power Relay Coil Circuit Failure #

Note: The description of code C1110 may vary depending on the vehicle manufacturer.

Known label variations:

• ABS Power Relay Coil Circuit Malfunction (Nissan, Infiniti)
• ABS Motor Relay Circuit Failure (Hyundai, Kia)
• ABS Relay Circuit Open or Short (Mazda, Ford)

Summary of DTC C1110 #

Diagnostic Trouble Code C1110 indicates an issue detected in the Anti-lock Braking System (ABS) power relay coil circuit. In simple terms, the ABS module has found a problem with the electrical circuit that controls the relay responsible for powering the ABS pump or system. The relay is a switch operated by an electromagnet (the coil), allowing the ABS module to turn ABS functions on or off. If the circuit is open, shorted, or otherwise malfunctioning, the system may not function as intended. This code is most commonly found on Nissan, Infiniti, Hyundai, and Mazda vehicles but may appear on other makes as well. The ABS warning light usually illuminates on the dashboard, alerting the driver to a potential safety concern.

Frequent Symptoms for code C1110 #

A vehicle experiencing a C1110 code will typically show clear warning signs. Some symptoms may be subtle, but others are impossible to ignore. Most notably, the ABS warning light will remain on, signaling a problem with the system. The driver might notice changes in braking performance, especially during hard stops or slippery conditions. In many cases, the vehicle’s anti-lock braking system will be disabled, reverting to standard braking only. Other warning lights related to traction or stability control may also appear if those systems are linked to the ABS.

• ABS warning light illuminated
• Traction control or stability control lights may also be on
• ABS no longer functioning; standard brakes only
• Possible longer stopping distances on slick surfaces
• Unusual clicking or buzzing noises at startup (as the relay tries to engage)

Probable Causes for code C1110 (in order of frequency) #

C1110 is most often triggered by electrical faults in the ABS relay circuit, but the underlying causes can vary. Understanding the most common sources helps streamline diagnosis and avoid unnecessary repairs. Here are the most frequent culprits, ordered from most to least likely:

1. Faulty ABS power relay (the relay itself is defective)
2. Blown fuse in the ABS circuit
3. Damaged or corroded wiring/connectors (open circuit or short to ground)
4. Faulty ABS module (internal relay coil driver failure)
5. Low battery voltage or poor electrical system ground

Step-by-Step Diagnosis for code C1110 #

Diagnosing a C1110 code involves systematic checks of the relay, wiring, and related components. Always start with the basics and move to more complex tests if needed. Here’s a logical step-by-step approach:

• Confirm the code with a scan tool and note any related codes.
• Check the ABS fuse(s) for continuity; replace if blown.
• Locate the ABS power relay and visually inspect for signs of overheating or damage.
• Test the relay by swapping with a known good relay of the same type, if available.
• Inspect wiring and connectors between the ABS module, relay, and battery for corrosion, looseness, or damage.
• Test for voltage at the relay control and power terminals with the key ON.
• Check ground connections near the ABS module and relay for cleanliness and tightness.
• If all else checks out, test the ABS module’s relay control output (may require OEM service information or advanced scan tools).

Possible Repairs for code C1110 #

Once you’ve pinpointed the cause, repairs can be straightforward or require specialized parts. Here are the most common solutions corresponding to each root cause:

• Replace faulty ABS power relay (most frequent repair)
• Replace blown ABS fuse and inspect for root cause
• Repair or replace damaged/corroded wiring or connectors in the ABS circuit
• Clean and tighten battery and ground cable connections
• If ABS module failure is confirmed: replace or reprogram ABS control module (requires OEM tools/procedures)

Is It Safe to Drive with code C1110? #

Driving with code C1110 is not recommended, especially in adverse conditions. While the basic hydraulic brakes will still function, the anti-lock braking system is disabled. This means the wheels can lock up under hard braking or on slippery surfaces, increasing the risk of skidding or loss of control. Traction and stability systems may also be affected. Only drive the vehicle to a repair facility if absolutely necessary, and use extra caution.

Vehicles Most Commonly Affected by code C1110 #

C1110 is seen frequently in certain models, especially from Japanese and Korean OEMs. If you own one of these vehicles, be extra vigilant for warning lights and symptoms:

• Nissan Altima, Maxima, Murano, Pathfinder
• Infiniti G35, G37, FX35, QX60
• Hyundai Sonata, Santa Fe, Tucson
• Kia Optima, Sorento
• Mazda 3, Mazda 6, CX-5
• Ford (models with Mazda-derived ABS systems)

Common Errors & Best Practices for code C1110 #

Mistakes in diagnosing or repairing C1110 often stem from skipping steps or replacing parts without proper testing. Following best practices ensures a safe, lasting fix:

• Do not replace the ABS module before testing the relay and wiring
• Always check fuses and relay operation first—they are easy and inexpensive to replace
• When inspecting wiring, flex harnesses and connectors to reveal hidden corrosion or breaks
• After repairs, clear codes and road test the vehicle to confirm the issue is resolved
• Use OEM or high-quality replacement parts to prevent repeat failures

Quick FAQ for code C1110 #

Q: Can a weak battery trigger code C1110?
A: Yes, if the battery voltage drops too low, it can cause the ABS relay to malfunction or the ABS module to register a fault. Always check battery health when diagnosing electrical codes.

Q: Does replacing the ABS relay always fix C1110?
A: Not always. While a faulty relay is common, the root cause could also be wiring damage, bad fuses, or a failing ABS module. Proper diagnosis is key to avoid unnecessary part replacements.