C1112 — ABS Power Relay Coil Short Circuit To Ground #

Note: The code label may vary depending on vehicle manufacturer. Always refer to your vehicle’s OEM documentation for precise terminology.

• ABS Power Relay Coil Short Circuit To Ground (generic, multiple OEMs)
• ABS Pump Motor Relay Circuit Short to Ground (Nissan, Infiniti)
• ABS Control Module Power Relay Coil Short to Ground (Mazda, Ford)
• Hydraulic Brake Booster Power Relay Coil Short Circuit to Ground (Toyota, Lexus)

Code C1112 Summary #

The C1112 code indicates that the vehicle’s Anti-lock Braking System (ABS) has detected a short circuit to ground in the power relay coil circuit. The ABS is a safety system that prevents wheel lockup during emergency braking, maintaining traction and steering control. The power relay is an electronic switch that supplies electrical current to the ABS module or pump. When a short to ground occurs, the relay coil draws excessive current or fails to activate properly, disrupting ABS operation. This fault is typically triggered by wiring damage, a failed relay, or internal module issues. While the vehicle’s basic braking may function, ABS performance and related safety features can be compromised.

Common Symptoms for C1112 #

A vehicle with the C1112 code often exhibits warning signs that should not be ignored. These symptoms are designed to alert the driver to potential risks and loss of safety functions. Typical symptoms include:

• ABS warning light illuminated on the dashboard
• Traction Control System (TCS) or Electronic Stability Control (ESC) lights may also be on
• ABS system disabled; vehicle reverts to standard braking only
• Possible brake warning light
• Unusual clicking or buzzing noises from under the hood (ABS relay or pump attempting to operate)
• No noticeable change in normal braking under light/moderate use, but increased risk during emergency stops or slippery conditions

Likely Causes for C1112 #

The C1112 code is most commonly caused by electrical faults or component failures in the ABS relay circuit. The most frequent causes, in order of likelihood, are:

1. Damaged or shorted wiring between the ABS power relay and ground
2. Failed ABS power relay (internal coil shorted to ground)
3. Corroded or loose electrical connectors at the relay or ABS control module
4. Faulty ABS control module (rare, but possible if all else checks out)
5. Water intrusion leading to short circuits in the relay or harness

Step-by-Step Diagnosis for C1112 #

A methodical approach is essential to accurately diagnose and resolve the C1112 code. Use a digital multimeter and always consult the vehicle’s OEM wiring diagrams for reference. The typical diagnostic steps are as follows:

• Verify the code with a scan tool and document any related codes.
• Visually inspect the ABS relay, relay socket, and associated wiring for damage, corrosion, or loose connections.
• With the ignition off, disconnect the ABS relay and check coil resistance; compare with OEM specifications.
• Test the relay coil circuit for continuity to ground—there should be no direct short. If present, trace harness for damaged insulation.
• Check for voltage at the relay supply and ground circuits with the ignition on, as per wiring diagram.
• Substitute with a known-good relay if available; clear codes and retest system.
• If wiring and relay are confirmed good, further test the ABS control module output circuit for internal faults.

Possible Repairs for C1112 #

Based on the diagnostic findings, the following repairs are commonly performed to resolve the C1112 code:

• Repair or replace damaged wiring in the ABS relay circuit, using OEM-approved methods and materials.
• Replace the faulty ABS power relay with an OEM or high-quality equivalent part.
• Clean and secure electrical connectors at the relay, module, and fuse box; apply dielectric grease if appropriate.
• Address water ingress by sealing harness entry points and repairing any affected areas.
• Replace or reprogram the ABS control module only if all other repairs fail and module failure is confirmed.

Is It Safe to Drive with C1112? #

Driving with the C1112 code is NOT recommended, except for short distances in emergencies. While base braking remains operational, the absence of ABS dramatically increases the risk of wheel lockup, skidding, and loss of control, especially on wet or slippery roads. The vehicle’s stability and traction safety features may also be disabled. Immediate repair is strongly advised to restore full braking performance and safety compliance.

Vehicles Most Commonly Affected by C1112 #

The C1112 code can appear on a wide range of vehicles, but it is most frequently reported on models from manufacturers using similar ABS relay configurations. Vehicles commonly affected include:

• Nissan Altima, Maxima, Murano, Rogue, Frontier
• Infiniti QX-series, G35, FX35
• Mazda 3, Mazda 6, CX-5, CX-9
• Toyota Camry, Corolla, Highlander, Prius
• Ford Focus, Escape, Fusion

Common Mistakes & Best Practices for C1112 #

Avoiding misdiagnosis and unnecessary parts replacement is crucial when dealing with the C1112 code. Some frequent errors and professional tips include:

• Replacing the ABS module without first checking the relay and wiring—always test simpler, less expensive components first.
• Overlooking minor corrosion or loose pins in connectors, which can cause intermittent shorts.
• Ignoring water damage or leaks near the fuse/relay box—thoroughly inspect the area and address any sources of moisture.
• Neglecting to clear codes and road-test the vehicle after each repair step to confirm resolution.
• Always use OEM wiring diagrams and relay specifications for accurate diagnosis.

Quick FAQ for C1112 #

Here are answers to some common questions drivers and technicians ask about the C1112 code:

• Q: Can the C1112 code cause my car to fail inspection?
  A: Yes. In most regions, an illuminated ABS warning light or stored ABS code will cause a failed safety inspection until repaired.
• Q: Will replacing the ABS relay fix the code every time?
  A: Not always. While the relay is a common culprit, damaged wiring or a faulty module can also cause this code. Always perform a thorough diagnosis before replacing parts.