Motor/Generator A Temperature Sensor Circuit
The P0A1A code means the vehicle's onboard diagnostic system has detected: Motor/Generator A Temperature Sensor Circuit. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $300 - $800 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Hybrid system warning
- Possible reduced power output
- Motor/generator may be derated
Probable Causes (Ranked by Likelihood)
- Failed motor/generator temperature sensor Very High
- Damaged temperature sensor wiring High
- Corroded connector at temperature sensor Moderate
- Failed hybrid control module sensor input Low
Step-by-Step Diagnostic Procedure
-
Read motor/generator temperature from the scan tool and compare to expected values.
-
Check temperature sensor connector for corrosion.
-
Measure sensor resistance at known temperature.
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Inspect wiring between the sensor and control module.
Frequently Asked Questions
Why does the motor/generator have a temperature sensor?
Electric motors generate heat during operation. The sensor allows the control module to reduce motor power if temperatures approach unsafe levels.
Can a bad temperature sensor cause power loss?
Yes, if the sensor reads higher than actual temperature, the control module will unnecessarily limit motor power.
Is the motor/generator temperature sensor accessible?
The sensor is typically mounted on or within the motor/generator housing inside the transaxle. Access varies by vehicle.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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