What Does P0A47 Mean?
DTC P0A47 indicates the drive motor "B" position sensor circuit output has fallen below the minimum expected signal level. For a resolver-based position sensor, this means one or both resolver output signal amplitudes have dropped below the acceptable threshold, preventing the Hybrid Control Module from reliably determining rotor position. This can be caused by an open circuit in the resolver windings, signal wiring damage, or excessive air gap. The loss of adequate signal strength makes accurate motor commutation impossible, and the HCM will disable motor "B" operation.
Safety Warning
A low position sensor signal results in complete loss of motor "B" commutation control. The motor will be disabled, reducing total drive power and potentially eliminating AWD capability. Sudden power reduction may be unexpected by the driver.
Common Causes
30%
Open circuit in the motor "B" position sensor signal wiring
25%
Failed resolver with an open winding (excitation or signal)
20%
Disconnected or poorly seated sensor connector
15%
Excessive resolver air gap from severe bearing wear
10%
Corroded connector pins with high contact resistance attenuating the signal
Diagnostic Steps
1
Step 1: Check motor "B" position sensor data on the scan tool. A fixed zero or very low position reading confirms the low signal condition.
2
Step 2: Inspect the motor "B" position sensor connector for physical condition. Verify it is fully connected and locked. Check for corrosion or moisture.
3
Step 3: Measure resolver winding resistances at the sensor connector. An open reading (OL) on any winding indicates resolver failure. Compare all winding resistances to specifications.
4
Step 4: Test wire continuity from the sensor connector through to the inverter/HCM connector for all signal and excitation conductors. Check for opens in each wire individually.
5
Step 5: Verify the excitation signal is present at the sensor connector using an oscilloscope. If the excitation from the inverter is missing, the issue is in the inverter resolver driver circuit.
Estimated Repair Cost
$350 - $2,200
Parts + labor, varies by vehicle and location
DTC P0A47 indicates the drive motor "B" position sensor circuit output has fallen below the minimum expected signal level. For a resolver-based position sensor, this means one or both resolver output signal amplitudes have dropped below the acceptable threshold, preventing the Hybrid Control Module ...
The most common cause of P0A47 (Drive Motor "B" Position Sensor Circuit Low) is: Open circuit in the motor "B" position sensor signal wiring
Typical repair costs for P0A47 range from $350 to $2,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A low position sensor signal results in complete loss of motor "B" commutation control. The motor will be disabled, reducing total drive power and potentially eliminating AWD capability. Sudden power reduction may be unexpected by the driver.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0A47 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Hybrid/EV Drivetrain
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
