C1515 on Mazda: How to Diagnose & Fix
Torque Sensor Zero Point Adjustment Undone
1 Mazda model · 1 documented issue · $200-$1,200 repair
C1515 on Mazda by model: symptoms, diagnosis and fix
The NC Miata uses an electric power steering system that can fail due to a faulty steering angle sensor, EPS control module, or motor. When the system fails, the EPS warning light illuminates and power assist is lost, making the steering very heavy at low speeds. While the car remains drivable (it is manual rack-and-pinion underneath), parking and tight maneuvers become difficult.
Common Symptoms
- EPS warning light on dashboard
- Sudden loss of power steering assist
- Heavy steering at low speed
- Intermittent power steering assist
- Steering assist returns after restart
How to Fix
Diagnose with a Mazda scan tool to identify the specific failed component (sensor, module, or motor). The steering angle sensor is the most common failure and can be recalibrated or replaced relatively affordably. If the EPS motor or control module has failed, replacement costs are higher. Some owners have had success with used EPS units from junkyards ($200-$400).
Sources for this issue (1)
C1515 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 C1515 mean on a Mazda?
C1515 stands for "Torque Sensor Zero Point Adjustment Undone." C1515 is a manufacturer-specific code (Toyota/Lexus) indicating the electric power steering ECU has not had the steering torque sensor zero-point calibration performed. It is not necessarily a hardware failure; rather, the system needs the torque sensor's neutral/zero reference set. Until calibrated, the power steering assist, and sometimes traction and stability control, may be limited or disabled, and steering may feel heavy. It commonly appears after battery disconnection, steering or sensor service, or EPS module work. On Mazda it is documented across 1 model: MX-5 Miata.
What are the most common causes of C1515?
The most common causes of C1515 are: Zero-point calibration not performed after service/battery disconnect, EPS module, steering column, or torque sensor replaced without calibration, Faulty or misaligned steering torque sensor, Damaged wiring or connector to the torque sensor, Steering angle/zero reference lost, Low system voltage during calibration attempt. The specific cause varies by vehicle.
How much does it cost to fix C1515 on a Mazda?
Published repair estimates on Mazda range from $200 to $1,200 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for C1515 on a different make?
View C1515 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.