Motor/Generator B Performance
The P0A22 code means the vehicle's onboard diagnostic system has detected: Motor/Generator B Performance. This is a critical severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- hard
- Estimated cost
- $1,000 - $5,000 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Hybrid system warning light
- Noticeably reduced acceleration
- Unusual vibration during electric motor operation
Probable Causes (Ranked by Likelihood)
- Degraded motor/generator windings High
- Motor/generator bearing failure High
- Inverter malfunction limiting motor output Moderate
- Mechanical binding in transaxle Low
Step-by-Step Diagnostic Procedure
-
Monitor motor/generator performance data including torque output and efficiency.
-
Listen for unusual sounds from the transaxle during electric operation.
-
Check inverter output voltage and current during motor operation.
-
Inspect motor/generator coolant flow and temperature.
Frequently Asked Questions
Is P0A22 motor/generator replacement expensive?
Yes, replacement typically costs $1,500 to $5,000 including parts and labor. Remanufactured units can reduce costs.
Can motor/generator performance issues be repaired?
Bearing replacement or rewinding is possible with specialized equipment, but replacement with a new or remanufactured unit is usually more cost-effective.
What causes motor/generator degradation?
Over time, motor windings develop insulation breakdown from heat cycles, bearings wear, and magnets weaken. Extended overheating accelerates degradation.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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