Yaw Rate Sensor Circuit Malfunction
What does C0138 mean?
The C0138 code means the vehicle's onboard diagnostic system has detected: Yaw Rate Sensor Circuit Malfunction. This is a moderate severity code.
Common Symptoms
- Stability control light on
- Traction control light illuminated
- ESC system disabled
- Vehicle dynamics system warning
- Skid control system inoperative
Probable Causes (Ranked by Likelihood)
- Failed yaw rate sensor Very High
- Yaw rate sensor not calibrated High
- Sensor connector corrosion Moderate
- ESC module yaw rate input fault Low
Step-by-Step Diagnostic Procedure
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Scan ESC module for yaw rate DTCs
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Read yaw rate sensor data on level surface at rest
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Check sensor for proper mounting orientation
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Inspect connector for damage or corrosion
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Attempt yaw rate sensor recalibration
Frequently Asked Questions
What does a yaw rate sensor measure?
The yaw rate sensor measures the rotational rate of the vehicle around its vertical axis. In simple terms, it detects how quickly the vehicle is turning or spinning.
Is the yaw rate sensor the same as the lateral acceleration sensor?
No. The yaw rate sensor measures rotational movement while the lateral acceleration sensor measures side-to-side force. Both work together to provide complete vehicle dynamics data to the ESC system.
Can this sensor be affected by vehicle modifications?
Suspension lifts, large tire changes, and other modifications that alter the vehicle center of gravity can affect yaw rate readings and may require sensor recalibration.