What Does P0A48 Mean?
DTC P0A48 indicates the drive motor "B" position sensor circuit output exceeds the maximum expected signal level. The Hybrid Control Module has detected that the resolver or encoder output signals are abnormally high, which corrupts the rotor position calculation. This can be caused by short circuits in the sensor or wiring, excessive excitation voltage, or electromagnetic interference coupling into the signal path. The abnormally high signal creates unreliable position data, forcing the HCM to shut down motor "B" to prevent dangerous commutation errors.
Safety Warning
High position sensor signals can cause severe commutation errors if the motor is allowed to operate, potentially resulting in uncontrolled torque output. The HCM will disable motor "B" for safety, resulting in sudden loss of drive power from that motor.
Common Causes
30%
Short circuit between position sensor signal wires or to power supply
25%
Electromagnetic interference from motor phase cables coupling into unshielded resolver wiring
20%
Damaged wiring harness with compromised shielding near high-current conductors
15%
Inverter resolver excitation circuit outputting excessive voltage
10%
Internal sensor fault producing abnormally high signal output
Diagnostic Steps
1
Step 1: Check motor "B" position sensor live data for erratic, oscillating, or pegged-high readings that indicate the high circuit condition.
2
Step 2: Disconnect the motor "B" position sensor and check for short circuits between all wires in the harness. Test for shorts between signal pairs, shorts to excitation, and shorts to ground.
3
Step 3: Inspect the resolver wiring harness for physical damage, chafing, or melted insulation, particularly where it runs near motor phase cables or other high-current wiring.
4
Step 4: With the sensor connected, use an oscilloscope to measure resolver output amplitudes. Signals significantly above the specification indicate a circuit high condition. Check for noise superimposed on the signals.
5
Step 5: Verify the excitation signal amplitude at the sensor is within specification. An over-driven excitation will proportionally increase the output signal level.
Estimated Repair Cost
$350 - $2,200
Parts + labor, varies by vehicle and location
DTC P0A48 indicates the drive motor "B" position sensor circuit output exceeds the maximum expected signal level. The Hybrid Control Module has detected that the resolver or encoder output signals are abnormally high, which corrupts the rotor position calculation. This can be caused by short circuit...
The most common cause of P0A48 (Drive Motor "B" Position Sensor Circuit High) is: Short circuit between position sensor signal wires or to power supply
Typical repair costs for P0A48 range from $350 to $2,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
High position sensor signals can cause severe commutation errors if the motor is allowed to operate, potentially resulting in uncontrolled torque output. The HCM will disable motor "B" for safety, resulting in sudden loss of drive power from that motor.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0A48 to identify the root cause.
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Quick Info
Category
Powertrain
System
Hybrid/EV Drivetrain
Difficulty
Type
Generic (SAE)
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