C1115 — ABS Power Relay Output Short Circuit To Battery

chassis (brakes/steering/suspension)

Is it safe to drive?

Drive with caution The base brakes usually still work, so careful driving is possible — but ABS and stability control are disabled, which lengthens stopping distances on slippery roads. Fix promptly and avoid harsh driving.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm C1115 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many C0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the ABS / stability control for damage, corrosion, chafing or poor contact.
Subsystem check Read all four wheel speed PIDs while driving slowly — the faulty sensor drops out or reads implausibly.
Subsystem check Inspect the sensor and tone ring for metal debris and damage near the hub.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm C1115 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for C1115 (parts and labor, USD, independent shop rates): ABS module repair or replacement: $400–$1,200; Repair sensor wiring: $80–$250; Replace a wheel speed sensor: $120–$350. Overall, fixing C1115 usually costs between $80 and $1,200. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What is the most common cause of C1115?

The most common causes are: blown fuse or low voltage to the ABS module, damaged sensor wiring or corroded connector, failed wheel speed sensor.

What are the symptoms of C1115?

Drivers most often notice: ABS or ESC warning light on, ABS not operating during hard braking, brake pedal pulsation changes, speedometer or cruise control issues.

Is it safe to drive with C1115?

The base brakes usually still work, so careful driving is possible — but ABS and stability control are disabled, which lengthens stopping distances on slippery roads. Fix promptly and avoid harsh driving.

How much does it cost to fix C1115?

ABS module repair or replacement — $400–$1,200; Repair sensor wiring — $80–$250; Replace a wheel speed sensor — $120–$350. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

How do I diagnose C1115 myself?

Start with a scan: confirm C1115, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the ABS / stability control, and verify the suspect component against live data before buying parts.

When your vehicle's control unit logs code C1115, it's reporting a specific electrical problem within the anti-lock braking system. Specifically, the module has detected a short circuit to battery voltage on the ABS power relay output circuit. This places C1115 squarely in the chassis category of diagnostic trouble codes, dealing with the brakes, steering, and suspension systems rather than the engine or transmission.

The ABS module depends on reliable power delivery to operate its hydraulic pump, electronic valves, and control logic. When that power relay output gets shorted to battery voltage, the module can no longer regulate brake pressure during emergency stops. The control unit sets C1115 after monitoring sensor inputs over multiple drive cycles and finding that the readings fall outside the manufacturer's calibrated thresholds. It simultaneously captures a freeze frame snapshot—recording engine RPM, load, coolant temperature, and vehicle speed at the exact moment the fault occurred.

Symptoms of C1115

The ABS warning lamp illuminates on the instrument cluster
Anti-lock braking fails to activate during panic stops or low-traction maneuvers
The brake pedal may feel different, with altered pulsation feedback during braking
Speedometer accuracy can be affected, and cruise control may become unresponsive
A message appears indicating that stability control has been deactivated
In some cases, the traction control system also disables alongside ABS

Common Causes of C1115

The most frequent culprits for C1115 involve the wheel speed sensors and their associated wiring. These sensors constantly feed data to the ABS module, and any interruption or electrical fault in this circuit triggers the code. Beyond sensor issues, the problem can stem from several other sources.

Failed wheel speed sensors represent the leading cause, particularly in older vehicles with corroded or worn components. Damaged wiring or corroded connectors in the sensor circuit can create the short condition the control module detects. A faulty ABS module or failing pump motor may also generate the C1115 code when internal circuits short to battery voltage. Blown fuses or insufficient voltage supply to the ABS module prevent proper operation and can trigger the code. Finally, a damaged tone ring—sometimes called a reluctor ring—on the wheel hub assembly can cause erratic wheel speed readings that confuse the module.

How to Diagnose C1115

Systematic diagnosis prevents unnecessary part replacements and ensures the root cause gets addressed.

Connect an OBD2 scanner and retrieve all stored codes, paying special attention to C1115 and any accompanying codes. Save the freeze frame data associated with C1115—this recorded snapshot reveals engine conditions when the failure occurred and guides your testing.
Research whether your specific vehicle has any factory technical service bulletins related to C1115 or similar ABS concerns. Manufacturers occasionally publish software updates or known fixes for recurring issues.
Perform a thorough visual inspection of all wiring harnesses and connectors tied to the ABS system. Look for damaged insulation, corrosion buildup, chafed wires, or loose connections that could cause electrical shorts.
Using a scan tool capable of displaying live sensor data, monitor all four wheel speed PIDs while driving slowly in a safe location. A malfunctioning sensor will show dropped readings or implausible speed values compared to the others.
Physically examine each wheel speed sensor and its corresponding tone ring. Remove any accumulated metal debris and check for visible damage, cracks, or wear on the ring teeth.
After clearing the code, complete a full drive cycle that recreates the conditions captured in the freeze frame data. Monitor whether C1115 reappears or remains cleared.

Repair Options and Costs

Addressing the underlying cause rather than guessing saves both time and money. Here are the typical repair scenarios for C1115.

ABS module repair or replacement typically costs between $400 and $1,200, depending on whether you choose remanufactured units or new components. Wiring harness repair for damaged sensor circuits generally runs $80 to $250. Wheel speed sensor replacement—often the most straightforward fix—usually costs $120 to $350 per sensor.

Overall, fixing C1115 typically falls somewhere between $80 and $1,200 depending on the actual failure point. Spending time on accurate diagnosis before purchasing parts is worth the effort. The most expensive repair scenario should never be the first thing you try.

Driving Safety Verdict

Your standard friction brakes will continue functioning without ABS intervention, meaning controlled stops remain possible under normal conditions. However, anti-lock braking and electronic stability control will not operate until C1115 gets resolved. This becomes particularly dangerous on wet pavement, ice, gravel, or any low-grip surface where wheel lockup prevention matters most. The prudent approach: drive cautiously, avoid aggressive braking or high-speed maneuvering, and schedule repairs promptly. Treat this code as a caution-level issue—your vehicle stops, but not as safely as it should.