C0112 is a chassis-class diagnostic trouble code that indicates a fault in a wheel speed-related signal or plausibility check within the vehicle stability/anti‑lock braking system. This is a system-level SAE-style descriptor, not a definitive component failure; the exact meaning and which module or wheel is referenced can vary by make, model, and year. You should confirm the fault with basic electrical and network tests — power, ground, continuity, sensor signal amplitude/frequency and CAN (Controller Area Network) message presence — before replacing parts.
What Does C0112 Mean?
At the SAE level, C0112 is a chassis code reporting an abnormal wheel speed signal or circuit plausibility condition affecting stability/ABS (Anti‑Lock Brake System) related functions. This guide follows SAE J2012 formatting; standardized DTC descriptions are published in the SAE J2012DA digital annex.
C0112 is shown here without a hyphen FTB (Failure Type Byte). An FTB, if present, refines the symptom or failure mode (for example, open, short, intermittent, or specific plausibility failure). Because chassis C-codes often lack a single universal component-level definition, you must verify the exact fault with electrical checks and network/message verification for the vehicle in question.
Quick Reference
- Code class: C — chassis system (wheel speed/ABS signal level)
- Shown without FTB: no hyphen subtype included; an FTB would narrow the failure mode
- Primary tests: power, ground, continuity, sensor waveform, and CAN message presence
- Don’t assume: do not replace sensors or modules without confirming test evidence
- Commonly associated: wheel speed sensors, wiring/connectors, ABS/ESC module inputs, or bus communication issues
- Safety: steering/braking stability systems may be affected; drive cautiously until diagnosed
Real-World Example / Field Notes
Example 1 — Intermittent ABS lamp with stored C0112: A vehicle arrived with sporadic ABS lamp illumination. A quick scan showed C0112 set and intermittent wheel-speed plausibility flags. Technician checked the ABS module ground and found a loose chassis ground at a nearby bolt; after cleaning and securing the ground, the wheel-speed waveform returned to normal and the code did not repeat. Lesson: shared or corroded grounds commonly produce plausibility faults that mimic sensor failure.
Additional note — signal correlation: C0112 often indicates that wheel-speed values reported across modules (ABS, transmission, instrument cluster) do not match expected relationships. Always compare module-to-module values with live data before condemning a sensor.
What Does C0112 Mean?
C0112 is an SAE-style chassis code. In SAE J2012 formatting the leading “C” designates a chassis system. The code structure and standardized short descriptions follow the SAE J2012DA digital annex; this guide follows that formatting and terminology. The code shown here does not include a hyphen Failure Type Byte (FTB); when present an FTB narrows the subtype or failure mode (for example, a specific plausibility or signal pattern), but the base C0112 entry remains the system-level flag.
Because many chassis C-codes do not map to a single universal component, the exact definition and affected input can vary by make, model, and year. Confirm the vehicle-specific meaning by checking the manufacturer’s wiring diagrams and verifying sensor waveforms, power/ground, connector integrity, and CAN (Controller Area Network) or LIN (Local Interconnect Network) message presence with a capable scan tool or oscilloscope.
Quick Reference
- Code class: C — chassis system plausibility/correlation
- Shown without FTB: no hyphen subtype included; an FTB would indicate a more specific failure pattern
- Primary focus: wheel-speed signal plausibility, wiring/connectors, and control-module inputs
- Key tests: sensor waveform, power/ground, continuity, resistance, and CAN/LIN message checks
- Diagnostic approach: test-driven—verify symptoms, gather data, test to confirm before repair
- Safety note: braking and stability assistance may be reduced; drive cautiously
Real-World Example / Field Notes
Example 1 — Intermittent ABS lamp and C0112: A car arrived with the ABS lamp coming on intermittently. Scan data showed a plausibility flag for wheel-speed inputs with no single sensor permanently failed. The technician inspected grounds and found a loose chassis ground near the ABS module. After cleaning the contact and tightening the ground, live wheel-speed waveforms became stable on the oscilloscope and the code did not return.
Example 2 — Corroded sensor connector producing implausible pulses: One vehicle had C0112 set after water intrusion at a wheel-speed sensor connector. The scope showed erratic pulse amplitudes and missing edges; resistance and continuity checks were inconsistent with the expected sensor pattern. Repair consisted of replacing the damaged pigtail/connector and confirming steady AC or digital pulse waveforms at speed. Final verification was a CAN-message correlation check between the ABS module and instrument cluster showing consistent speed data.
Example 3 — Network message mismatch or module input fault: In a truck, C0112 appeared alongside inconsistent wheel-speed data seen in the ABS and a separate transmission control module. The fault traced to intermittent CAN bus voltage on one segment due to a damaged shield and a chafed CAN high conductor. After repairing the wiring and confirming stable recessive/dominant voltages and expected message IDs with a scan tool, the plausibility flags cleared.
Summary: C0112 can stem from sensor, wiring, connector, ground, tone-ring, or communication faults. Use targeted tests to localize the cause rather than assuming a single failed part.
Chassis wheel speed circuit faults often show symptoms only under certain conditions (moisture, vibration, temperature changes); be prepared to reproduce conditions during diagnosis.
Symptoms of C0112
- Warning lamp Illuminated ABS/Anti-lock Braking System (ABS) and/or stability lights on the dash.
- Loss of function Reduced or disabled ABS/ESC/traction control intervention during hard braking or slippery conditions.
- Inconsistent speed One wheel speed value shows zero or erratic on a scan tool while others are steady.
- Pulsation Brake pedal pulsation or unexpected ABS activity during normal braking.
- Intermittent fault Code appears and clears intermittently, often with moisture or after driving through water.
- Diagnostic presence C0112 stored in the chassis control module or ABS module’s memory and repeatable in freeze-frame data.
Common Causes of C0112
Most Common Causes
- Open or short in the wheel speed sensor signal wiring or connector commonly associated with corrosion, chafing, or damaged insulation.
- Poor sensor-to-module reference ground or lost 12V/ignition-switched supply to the sensor circuit.
- Contaminated or damaged wheel speed sensor tone ring (reluctor) producing an implausible signal.
- Corroded connector terminals or poor pin contact at the ABS/Anti-lock Braking System (ABS) module or harness splice.
Less Common Causes
- Internal failure of the ABS/Anti-lock Braking System (ABS) control unit or chassis module controlling wheel speed inputs.
- Controller Area Network (CAN) bus communication errors or low-voltage supply issues causing incorrect or missing wheel speed messages.
- Intermittent ground faults elsewhere in the vehicle that upset sensor reference circuits.
- Aftermarket equipment or incorrect repairs altering sensor wiring routing and introducing interference.
Diagnosis: Step-by-Step Guide
Tools: full-function scan tool with live data and freeze-frame, digital multimeter (DMM), oscilloscope with inductive pickup, wiring diagrams, backprobe pins, continuity tester, inspection light, basic hand tools, dielectric grease, and a CAN bus tester or scope for network checks.
- Verify the concern: Confirm the dash warnings and record when the code set (driving conditions, speed, wet/dry). Note freeze-frame data and which module stored C0112.
- Collect data: Use the scan tool to view live wheel speed parameters and Mode $06 if available. Check whether the suspected circuit shows zero, erratic, or no signal compared to other wheels.
- Evaluate likely causes: Compare wiring diagrams to locate sensor power, ground, and signal paths. Identify connectors, splices, and nearby components that often fail on the vehicle.
- Inspect visually: Examine harness, sensor connector, and tone ring for damage, corrosion, or debris. Wiggle test connectors while watching live data for intermittent changes; consistent change indicates wiring/connector issue.
- Test power/ground: With ignition on, backprobe sensor power and ground. A missing or low supply/ground confirms supply-side fault; correct reading (near battery voltage and low ohms to ground) moves you to signal testing.
- Signal test: Spin the wheel by hand or lift and run at low speed while monitoring with an oscilloscope or the scan tool. A healthy sensor produces a clean AC or digital pulse waveform; an absent or noisy waveform confirms sensor or tone ring/circuit trouble.
- Check continuity and resistance: With power off, measure sensor resistance and continuity to the module. Open circuit or short to chassis/12V confirms wiring fault. Replace or repair only when measurements point to a single failing item.
- CAN/ECU checks: If sensor signals look correct but module reports no valid input, verify Controller Area Network (CAN) health and module power/grounds. Use a CAN tester or scope to check message consistency; loss of expected messages implicates network or module faults.
- Repair candidate verification: After identifying a suspect (connector repair, sensor, harness splice, or module), perform the specific repair and re-test the same measurements to confirm correction—do not replace parts without this confirmation.
- Final verification: Clear codes, run the vehicle through the same conditions that produced the code, and confirm the live data and ABS/Anti-lock Braking System (ABS) indicators return to normal before closing the job.
Professional tip: Always reproduce the fault with live data and waveform capture before replacing components. Intermittent wiring faults and poor connectors are far more common than outright sensor failures—backprobe and wiggle tests are quick ways to catch these. Ensure you confirm a repair with the same test that originally showed the fault.
Possible Fixes & Repair Costs
Repairs for C0112 depend on what your tests confirm. Low-cost fixes are simple: clean or reseat a connector after finding corrosion or intermittent continuity on the harness; replace a short pigtail at a damaged plug; or clear a false code after resolving a loose ground. Typical repairs include replacing a wheel speed sensor assembly or repairing wiring harness sections confirmed to be open/short by continuity and voltage tests. High-cost jobs involve replacing or reprogramming an ABS/ESC controller or repairing a CAN bus segment after diagnosing corrupted frames or module faults with a scope or advanced scanner.
- Low: $50–$150 — justified when inspection shows a loose/dirty connector or a short pigtail; continuity and connector voltage checks confirm restoration after cleaning or splicing.
- Typical: $200–$600 — sensor replacement or targeted wiring repair; justified when a sensor signal fails plausibility or continuity tests or Mode 06/live data shows no pulse from that circuit.
- High: $800–$2,000+ — module replacement, CAN bus repair, or extensive harness replacement; justified only after benching modules, observing failed CAN diagnostics, or confirming module I/O faults with a scope and known-good module substitution.
Factors affecting cost: labor rates, OEM vs aftermarket parts, need for module programming, diagnostic time, and hard-to-reach harness runs. Never replace parts without a confirming test: a multimeter, oscilloscope, and bi-directional scan tests should show the exact failure mode before authorizing expensive repairs.
Can I Still Drive With C0112?
You may be able to drive short distances with C0112, but it depends on what systems rely on the affected wheel speed signal. If the code indicates an intermittent or missing wheel speed circuit, traction control, anti-lock braking, or stability control may be limited or disabled. That increases risk in low-traction conditions. Use caution, avoid high speeds and slick roads, and prioritize diagnosis. If braking feels different or ABS warnings are active, stop driving and tow for safety.
What Happens If You Ignore C0112?
Ignoring C0112 can leave ABS, traction control, or electronic stability control inoperative or degraded and may mask related faults in the wheel speed network. You risk reduced braking performance in emergencies and loss of stability aids. Additionally, an unresolved electrical fault can worsen, causing intermittent drivability or additional module faults that increase repair cost.
Related Codes
- C0194 – Chassis Wheel Speed Signal Plausibility
- C0193 – Traction Control Torque Request Signal Range/Performance
- C0192 – Chassis Wheel Speed Signal Plausibility
- C0191 – Traction Control Torque Request Signal Low
- C0190 – Traction Control Torque Request Signal
- C0189 – Brake Wheel Speed Signal Plausibility
- C0188 – Stop Lamp Switch Circuit Range/Performance
- C0187 – Brake Wheel Speed Signal Plausibility
- C0186 – Chassis Wheel Speed Sensor Circuit Fault
- C0185 – Chassis Wheel Speed Signal Plausibility
Key Takeaways
- System-level fault: C0112 is a chassis circuit diagnostic code tied to a wheel speed signal pathway; the exact meaning varies by make/model/year and follows SAE J2012 formatting.
- Test first: Use a structured, test-driven approach — verify, scan, measure, and confirm before replacing parts.
- Common targets: wiring, connectors, sensor plausibility, power/ground, and CAN/LIN communications.
- Safety: Treat as potentially affecting ABS/ESC/TCS; avoid risky driving until diagnosed.
Vehicles Commonly Affected by C0112
C0112 is commonly seen across many ABS-equipped passenger cars and light trucks from European, Japanese, and American manufacturers. It is often reported on vehicles from Toyota, Honda, Ford, Chevrolet, BMW, and Mercedes in aftermarket and workshop notes, typically on models with wheel speed sensing and electronic stability systems. Exact definitions and affected modules can vary by make, model, and year—confirm with manufacturer wiring diagrams and basic electrical/CAN testing.
FAQ
Can I clear C0112 and hope it stays gone?
Clearing the code will turn off the lamp until the fault repeats, but it does not fix the underlying issue. If the fault is intermittent you might not see the code immediately, yet the condition can return and affect ABS/ESC behavior. Always perform a scan, record freeze-frame or Mode 06 data, and run electrical tests (voltage, continuity, signal) before and after clearing to verify a lasting repair.
Can a bad wheel speed sensor cause C0112?
Yes, a wheel speed sensor is a common possible cause, but C0112 does not guarantee the sensor is the failed item. Confirm by checking sensor power/reference, ground, and signal with a lab scope or multimeter while rotating the wheel. A plausible test result that justifies replacing the sensor is a missing or non-variable signal despite correct reference voltage and good wiring continuity.
Is this code a safety issue?
Potentially yes. C0112 concerns signals used by anti-lock braking and stability systems. If those systems are disabled or limited, vehicle stopping and stability in low-traction events can be compromised. Assess the vehicle’s warnings and braking feel; if ABS or traction control lights are on, avoid driving in hazardous conditions until diagnosis and repair are complete.
How long does diagnosis usually take?
Diagnosis time varies: 1–3 hours for basic checks (scan, inspect connectors, continuity tests), longer if intermittent wiring or CAN bus faults exist. Precise diagnosis requires live-data capture, scope traces, and possibly swapping or bench-testing modules. Always charge diagnostic time; it’s better to find the root cause than to replace parts repeatedly without confirmation.
Do I need dealer tools or can an independent shop fix C0112?
Often an independent shop with a quality scan tool, oscilloscope, and wiring diagrams can diagnose and repair C0112. Some vehicles require OEM-level programming or module coding after replacement, which may need dealer tools or a capable independent shop with pass-through programming. Confirm whether post-replacement programming is required by checking service literature and scan tool capability before ordering parts.
Quick Glossary
- ABS: Anti-lock Braking System. Helps prevent wheel lock-up during hard braking.
- ESC: Electronic Stability Control. Uses braking/torque control to help keep the vehicle stable.
- TCS: Traction Control System. Reduces wheelspin by applying brakes and/or reducing engine power.
- CAN: Controller Area Network. Vehicle communication bus used by control modules to share data.
- Wheel speed sensor: Sensor that reports wheel rotation speed to ABS/ESC systems.
- Open circuit: Broken circuit path (no continuity), often due to a cut wire, unplugged connector, or failed component.
- Intermittent: Comes and goes. Often caused by a loose connection, vibration, moisture, or internal component failure.
- Reference voltage: A stable voltage supplied by a module (often 5V) used by sensors for accurate readings.