C0040 on Toyota
Right Front Wheel Speed Sensor Circuit
C0040 on Toyota vehicles indicates right front wheel speed sensor circuit. Au7o has documented this code across 1 Toyota model — most commonly on Yaris. This is a brake/ABS-system code. The right front wheel speed sensor measures how fast that wheel is rotating and feeds that data to the anti-lock brake, traction control, and stability control systems. C0040 means the ABS module found an electrical problem in the right front wheel speed sensor circuit — for example an open circuit, a short, or a signal that is missing or out of range. You'll normally see the ABS and traction/stability lights come on, and those systems may shut off temporarily while your regular brakes keep working. Typical repair costs on Toyota range from $20 to $700, depending on the specific model and root cause.
Common Causes of C0040
- •Failed right front wheel speed sensor
- •Damaged, corroded or unplugged sensor wiring/connector
- •Damaged or rust-clogged tone/reluctor ring
- •Excessive air gap between sensor and tone ring
- •Wheel bearing wear affecting an integrated sensor
- •Water intrusion or corrosion at the connector
- •Faulty ABS control module (less common)
C0040 on Toyota by Model
Toyota Yaris(1 issue)
- Rear Wheel Speed Sensor Corrosion at the Hub Connector (ABS and Brake Warning Lights)2007-2018
A very common Yaris electrical fault: the rear wheel speed sensor is integrated into the rear hub/bearing assembly and is not sold separately. The weather seal where the harness plugs into the hub has a gap, so road spray and winter salt wick into the connector, corrode the pins and degrade the signal. The ABS light and the red brake/'!' light come on together, often intermittently at first and worse in wet or winter weather. Dealers routinely quote a complete rear hub assembly (owners report $650-750 CAD per side) when the actual fault is frequently just a dirty, corroded connector.
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View C0040 across all makes →Frequently Asked Questions
What does C0040 mean on Toyota?▼
C0040 stands for "Right Front Wheel Speed Sensor Circuit." This is a brake/ABS-system code. The right front wheel speed sensor measures how fast that wheel is rotating and feeds that data to the anti-lock brake, traction control, and stability control systems. C0040 means the ABS module found an electrical problem in the right front wheel speed sensor circuit — for example an open circuit, a short, or a signal that is missing or out of range. You'll normally see the ABS and traction/stability lights come on, and those systems may shut off temporarily while your regular brakes keep working. On Toyota specifically, this code is documented across 1 model.
What causes C0040 on Toyota vehicles?▼
Common causes on Toyota: Failed right front wheel speed sensor, Damaged, corroded or unplugged sensor wiring/connector, Damaged or rust-clogged tone/reluctor ring, Excessive air gap between sensor and tone ring, Wheel bearing wear affecting an integrated sensor. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix C0040 on a Toyota?▼
Repair costs on Toyota range from $20 to $700, depending on the specific model and root cause.
Which Toyota models have C0040 documented?▼
Au7o has documented C0040 on 1 Toyota model: Yaris.