C0035 on 2012-2016 Subaru Impreza: Wheel Speed Sensor Fault Explained

What's Unique About the 2012-2016 Subaru Impreza

For this generation of Subaru Impreza, the C0035 code's ambiguity is the most notable issue. Unlike some manufacturers that have a clear and consistent definition for this code, Subaru's specific definition is not well-documented in publicly available resources. This makes it critical for owners to rely on a proper diagnostic scan rather than generic code definitions before attempting a repair. This model and its platform mate, the XV Crosstrek, also have a known history of premature wheel bearing failures, which can sometimes be the root cause of a wheel speed sensor code.

Generation note: The 2012-2016 Subaru Impreza belongs to a single generation (fourth generation, GJ/GP series). This guide applies to all non-WRX/STI models within this year range.

Symptoms You May Notice

• ABS warning light is on
• Traction Control or Vehicle Dynamics Control (VDC) warning light is on
• Hill Start Assist warning light may be on
• ABS and traction control systems are disabled

Most Likely Causes

1. Damaged or Corroded Wheel Speed Sensor Wiring 🔴 High Probability → Shop ABS Wheel Speed Sensor The wiring harness is exposed to road debris, moisture, and constant movement from the suspension, which can lead to chafing, breaks, or corrosion in the connector pins.
   How to confirm: Visually inspect the entire length of the wiring from the wheel speed sensor up into the engine bay. Check for cracks, chafing, or green/white corrosion at the connector. Perform a 'wiggle test' on the harness while monitoring live data on a scan tool to find intermittent breaks.
   Typical fix: Repair the damaged section of wire or replace the connector. In severe cases, the entire sensor harness may need replacement.
   Est. part cost: $10-$50 for wire repair supplies
2. Failed Wheel Speed Sensor 🔴 High Probability → Shop ABS Wheel Speed Sensor
   How to confirm: After confirming the correct wheel with a scanner, use a multimeter to check the sensor's resistance and compare it to the manufacturer's specification. A reading of 'OL' (open loop) indicates a failed sensor. A scan tool can also view live data to see if the sensor is reporting speed while the wheel is spun.
   Typical fix: Replace the faulty wheel speed sensor. The sensor is typically held in by a single 10mm bolt on the wheel hub/knuckle. The plastic body of the sensor can become seized in the knuckle; use penetrating oil and gentle twisting with pliers to remove it, being careful not to break it off.
   Est. part cost: $80-$250
3. Debris or Rust on Sensor or Tone Ring 🟡 Medium Probability The sensor's magnetic tip and the tone ring (part of the wheel hub/bearing assembly) can accumulate metallic debris and rust, which weakens the signal.
   How to confirm: Remove the wheel speed sensor and inspect its tip for metal filings or rust. Inspect the tone ring through the sensor mounting hole for damage or heavy corrosion.
   Typical fix: Clean the sensor tip and the tone ring. If the tone ring is integrated into the wheel hub and is severely damaged, the entire hub assembly must be replaced.
   Est. part cost: $0 for cleaning, $150-$300 for a new wheel hub assembly

Rare But Worth Checking

• Faulty ABS Control Module: → Shop ABS Control Module This is rare and should only be considered after all other possibilities (sensor, wiring, hub) have been eliminated. It will often be accompanied by other codes, such as U0121 (loss of communication).
• Failing Wheel Hub/Bearing: A worn and loose wheel bearing can create excessive movement (wobble), changing the air gap between the sensor and the tone ring and causing an erratic signal. This is usually accompanied by a humming or grinding noise from the wheel that changes with speed. Premature wheel bearing failure is a known issue on this platform.

Diagnosis Steps

1. Connect an ABS-capable OBD-II scanner to the vehicle.
2. Read the fault codes. Confirm the full code definition, which should specify 'Left Front' or 'Right Front'.
3. If the location is confirmed, raise and safely support the vehicle on jack stands.
4. Remove the wheel corresponding to the fault code.
5. Visually inspect the wheel speed sensor and its wiring harness for any obvious damage, corrosion, or loose connections.
6. If wiring looks good, disconnect the sensor and use a multimeter to test its internal resistance. Compare the reading to the manufacturer's specifications. An open or shorted circuit indicates a bad sensor.
7. If the sensor tests good, inspect the tone ring (part of the wheel hub) for damage, debris, or excessive rust.
8. Check for play in the wheel bearing, which could indicate a failing hub assembly.
9. If replacing the sensor, torque the 10mm sensor bolt to 5.5 ft-lbs and the 12mm harness bracket bolt to 24 ft-lbs.
10. If the sensor, wiring, and hub appear to be in good condition, the fault may lie within the ABS control module, which requires advanced diagnostics.

Parts You'll Likely Need

• Front Wheel Speed Sensor (OEM #Bosch W0133-1990694 (Left), Bosch W0133-1990695 (Right)) — This is the most common failure point for a wheel speed sensor circuit code. The sensor itself can fail internally or the attached wiring can be damaged.
  Trusted brands: Bosch, NTK, Standard Motor Products (SMP), Duralast
  OEM price range: $150-$250
  Aftermarket price range: $80-$160
• Front Wheel Hub and Bearing Assembly (OEM #28373FG000) — If the tone ring, which is integrated into the hub, is damaged, or if the bearing has failed and is causing excessive wobble, the entire hub assembly must be replaced. Premature failure of this part is a known weakness on this platform.
  Trusted brands: Timken, SKF, MOOG, Subaru OE
  OEM price range: $250-$350
  Aftermarket price range: $150-$250

Related Codes That Often Appear With This One

• C0040 — C0040 is the code for the other front wheel speed sensor. Seeing them together could indicate a wiring issue common to both sides or a problem with the ABS module.
• U0121 — This code means 'Lost Communication With ABS Control Module.' If you see this with C0035, it points towards a more serious issue like a faulty ABS module, a blown fuse, or a major power/ground problem for the entire system.

Platform-Specific Known Issues

• A recall for the brake light switch (NHTSA 18V772000) can cause multiple warning lights, including for the VDC system. While it won't typically set a C0035 code, it's a known electrical issue in the brake system worth being aware of.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Excessive Engine Oil Consumption 🔴 High — Common enough to prompt a class-action lawsuit and TSBs. Affects 2.0L FB20 engines primarily in 2012-2013 models. The issue is excessive consumption (e.g., more than 1/3 quart per 1200 miles) due to faulty piston rings. (Ref: TSB 02-157-14R outlines the oil consumption test and the remedy, which was updated from piston ring replacement to a full short block replacement.)
• CVT (TR580) Failure or Malfunction 🔴 High — Widespread enough that Subaru extended the powertrain warranty for the CVT to 10 years / 100,000 miles. Symptoms include hesitation, shuddering, or outright failure. (Ref: TSB 16-107-17 and 16-115-18 detail the warranty extension for 2012-2015 and 2016-2017 models, respectively.)
• Brake Light Switch Failure 🔴 High — Subject to a major recall. The switch can malfunction due to contaminant exposure, preventing brake lights from illuminating and potentially preventing the vehicle from starting or shifting out of park. (Ref: NHTSA Recall 18V772000)
• Premature Wheel Bearing Failure 🟠 Medium — Owner communities and mechanics report that front and rear wheel bearings can fail earlier than expected, sometimes under 50,000 miles. Symptoms include a loud humming or grinding noise that changes with vehicle speed.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• C0036 — This is the companion code for the Right Front Wheel Speed Sensor, often diagnosed using the same procedures as C0035 (Left Front).
• C0045 — Relates to Rear Wheel Speed Sensor faults; these sensors are also prone to wiring damage from road debris and suspension movement similar to the front sensors.
• P0500 — Vehicle Speed Sensor malfunction; may trigger if the ABS control module cannot reconcile data from the wheel speed sensors to determine vehicle speed.
• C0074 — Pressure Sensor Requested Signal Malfunction; often appears when the VDC/ABS system is disabled due to a primary sensor fault like C0035.

Frequently Asked Questions