C0037: How to Diagnose & Fix — Left Rear Wheel Speed Sensor Circuit
3 vehicles · 2 makes · $120-$2,000 repair
How to diagnose and fix C0037: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Volkswagen Jetta · 2000–2001
Complaint data show a recurring pattern of ABS warning lights, chimes, and unexpected ABS activation at low speeds, sometimes causing longer stopping distances or abrupt brake behavior. The issue is reinforced by a recall covering short circuits within the ABS electronic control unit on certain early Jettas.
Common Symptoms
- ABS warning light and warning chime
- ABS activates at very low speed on dry pavement
- Brake pedal pulsates unexpectedly
- Longer stopping distance near a stop
- Traction control or brake warnings accompany ABS fault
How to Fix
Diagnosis should include scanning the ABS module, checking wheel speed sensor signals, and evaluating the ABS control module for internal faults. Repairs range from wheel speed sensor replacement to ABS module repair or replacement, with brake hydraulic inspection if the pedal behavior is abnormal. Costs typically range from $150 for a sensor issue to $1,200 for module replacement.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Bosch 0986594001 front-left ABS wheel-speed sensor
replace a graph- and circuit-tested failed front-left wheel-speed sensor causing signal dropout Fitment/availability: Bosch application catalog covers 1993-2005 Volkswagen Jetta; 68-mm front-left sensor cross-references 1J0927803, so con…
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Owner tips & cautions
- TipIf ABS activates below 10 mph on dry roads, inspect wheel speed sensor tone rings and sensor readings before replacing major brake parts.
- TipPersistent ABS and brake warnings after sensor checks often point to an internal ABS module fault.
Ford Transit Connect · 2014–2021
Transit Connect owners report intermittent ABS and traction control warnings caused by wheel speed sensor signal dropouts, often due to sensor contamination, corrosion at connectors, or damaged wiring near the hubs. The issue can be intermittent and may also disable stability control functions until repaired. This pattern appears in NHTSA complaints and owner reports describing ABS/AdvanceTrac warnings and sensor replacement.
Common Symptoms
- ABS warning light illuminated
- Traction control/AdvanceTrac warning
- ABS activates unexpectedly at low speed (sometimes)
- Speedometer fluctuation (rare)
- Stored wheel speed sensor DTCs
How to Fix
Scan ABS module for wheel speed sensor DTCs and view live wheel speed data to identify the affected corner. Clean/inspect tone rings (if applicable), repair wiring/connectors, or replace the wheel speed sensor; clear codes and verify on a road test.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- ABS Wheel Speed SensorCross-refSS20881
Fitment confirmed against the ShowMeTheParts catalog for this vehicle's year and engine.
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Sources for this issue (1)
Volkswagen Touareg · 2004–2010
The ABS hydraulic module and pump assembly fails, triggering ABS, traction control, and stability control warning lights. The module is expensive and mounted in a location prone to moisture intrusion. Can cause complete loss of ABS function.
Common Symptoms
- ABS warning light on
- Traction control light on
- ESP light on
- ABS not functioning
- Pump motor running constantly
How to Fix
Replace or rebuild the ABS module. Rebuilt units are available at lower cost. The system requires bleeding with a diagnostic tool (VCDS or VW scan tool) after replacement.
Find C0037 by make
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C0037 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does C0037 mean?
C0037 stands for "Left Rear Wheel Speed Sensor Circuit." C0037 is a generic OBD-II chassis code indicating a fault in the left-rear wheel speed sensor circuit. This sensor reports how fast the left-rear wheel is turning to the ABS, traction control, and stability control systems. When the module loses or sees an invalid signal from this sensor, it sets the code and typically disables ABS and traction/stability control, illuminating those warning lights. Regular braking remains functional, but the anti-lock and stability features may be inactive.
What are the most common causes of C0037?
The most common causes of C0037 are: Damaged or corroded wiring near the sensor, Failed left-rear wheel speed sensor, Corroded or loose sensor connector, Damaged tone/reluctor ring or excessive air gap, Debris, rust, or metal shavings at the sensor tip, Open or short in the sensor circuit, ABS module fault or loss of communication. The specific cause varies by vehicle.
How much does it cost to fix C0037?
Repair costs for C0037 range from $120 to $2,000, depending on the vehicle and root cause.
Which vehicles are affected by C0037?
Au7o has documented C0037 across 3 vehicle models from 2 manufacturers: Ford, Volkswagen.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.