What Does P0A55 Mean?
DTC P0A55 indicates a general malfunction in the current sensor circuit for drive motor "B" (the secondary traction motor or rear motor in AWD hybrid configurations). This sensor measures electrical current through motor B's phases, enabling precise torque control and overcurrent protection. A circuit fault means the hybrid control module cannot reliably measure motor B current, compromising torque distribution and safety monitoring for the secondary drive axis.
Safety Warning
Loss of motor B current sensing disables torque output from the secondary drive motor. In AWD configurations, this eliminates rear-axle power, significantly affecting traction on slippery surfaces and degrading overall vehicle stability under acceleration.
Common Causes
30%
Drive motor B current sensor failure or electrical open
25%
Wiring harness damage between motor B current sensor and control module
20%
Corroded or loose connector at the rear motor inverter assembly
15%
Rear motor inverter module internal current sensing fault
10%
Water intrusion into the motor B current sensor or connector area
Diagnostic Steps
1
Step 1: Retrieve freeze frame data noting motor B torque command, speed, battery voltage, and any concurrent DTCs for motor B or the rear inverter.
2
Step 2: Inspect the motor B current sensor wiring and inverter connectors for physical damage, corrosion, or evidence of water exposure.
3
Step 3: Monitor drive motor B current PIDs with the scan tool; check for zero readings, erratic values, or missing data that confirm the circuit fault.
4
Step 4: Verify the current sensor power supply and ground circuits measure within specification at the sensor connector.
5
Step 5: Replace the motor B current sensor or rear inverter assembly per manufacturer service procedures if the sensor is integrated.
Estimated Repair Cost
$400 - $2,500
Parts + labor, varies by vehicle and location
DTC P0A55 indicates a general malfunction in the current sensor circuit for drive motor "B" (the secondary traction motor or rear motor in AWD hybrid configurations). This sensor measures electrical current through motor B's phases, enabling precise torque control and overcurrent protection. A circu...
The most common cause of P0A55 (Drive Motor "B" Current Sensor Circuit) is: Drive motor B current sensor failure or electrical open
Typical repair costs for P0A55 range from $400 to $2,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Loss of motor B current sensing disables torque output from the secondary drive motor. In AWD configurations, this eliminates rear-axle power, significantly affecting traction on slippery surfaces and degrading overall vehicle stability under acceleration.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0A55 to identify the root cause.
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Quick Info
Category
Powertrain
System
Hybrid/EV Powertrain - Drive Motor B
Difficulty
Type
Generic (SAE)
Recommended Tools
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