What Does P0A56 Mean?
DTC P0A56 indicates the drive motor "B" current sensor readings are outside the expected range or do not properly correlate with commanded torque levels and motor speed. The control module detects that measured current deviates significantly from calculated expected values. This range/performance fault means the sensor is operational but producing inaccurate readings, which can cause incorrect torque delivery from motor B and compromise the vehicle's torque distribution strategy.
Common Causes
30%
Motor B current sensor calibration drift from thermal cycling or aging
25%
High-resistance connection in the sensor signal circuit
20%
Current sensor mounting displacement affecting accuracy
15%
Rear motor inverter partial fault causing actual vs. commanded current mismatch
10%
Drive motor B winding degradation causing abnormal current draw
Diagnostic Steps
1
Step 1: Review freeze frame data comparing reported motor B current against expected values for the torque command and operating speed.
2
Step 2: Monitor motor B phase current PIDs in real-time during a controlled test drive; compare phase balance and magnitude against motor A readings under similar loads.
3
Step 3: Inspect all current sensor wiring connections for high-resistance joints and verify pin contact integrity.
4
Step 4: Perform a current sensor zero-point calibration if supported by the manufacturer's diagnostic tool.
5
Step 5: Measure motor B phase-to-phase resistance to verify winding integrity; compare against specifications.
6
Step 6: If calibration and wiring are acceptable but the fault persists, replace the current sensor or rear inverter module.
Estimated Repair Cost
$300 - $2,200
Parts + labor, varies by vehicle and location
DTC P0A56 indicates the drive motor "B" current sensor readings are outside the expected range or do not properly correlate with commanded torque levels and motor speed. The control module detects that measured current deviates significantly from calculated expected values. This range/performance fa...
The most common cause of P0A56 (Drive Motor "B" Current Sensor Circuit Range/Performance) is: Motor B current sensor calibration drift from thermal cycling or aging
Typical repair costs for P0A56 range from $300 to $2,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Inaccurate motor B current sensing can lead to improper torque distribution between front and rear axles, potentially causing unexpected handling characteristics, especially during cornering or on slippery surfaces. The vehicle may reduce or disable motor B output as a protective measure.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0A56 to identify the root cause.
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Quick Info
Category
Powertrain
System
Hybrid/EV Powertrain - Drive Motor B
Difficulty
Type
Generic (SAE)
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