What Does P0A49 Mean?
DTC P0A49 indicates the drive motor "B" position sensor circuit is experiencing intermittent signal anomalies. The Hybrid Control Module has detected momentary signal dropouts, spikes, or noise bursts in the position sensor data that resolve on their own. These intermittent faults are concerning because even a brief loss of accurate position data during motor operation can cause commutation errors, resulting in torque disturbances or vibration. The intermittent nature makes diagnosis challenging as the fault may not be present during static testing.
Common Causes
35%
Loose or corroded connector terminals at the motor "B" position sensor
25%
Vibration-induced wire fatigue creating intermittent breaks in the resolver harness
15%
Intermittent shield ground connection allowing periodic EMI ingress
15%
Resolver with developing internal winding fault
10%
Motor bearing with intermittent play affecting resolver air gap under load
Diagnostic Steps
1
Step 1: Review freeze frame data and fault history to identify patterns in when the intermittent fault occurs (specific speeds, loads, temperatures, or vibration conditions).
2
Step 2: Monitor position sensor live data while performing a comprehensive wiggle test on the sensor connector, harness, and inverter connector. Apply vibration and flex to reproduce the intermittent.
3
Step 3: Inspect all connector terminals in the position sensor circuit for corrosion, reduced pin tension, or signs of arcing. Clean contacts and apply dielectric grease.
4
Step 4: Trace the resolver wiring harness for chafing, tight bends, or stress points near mounting brackets, grommets, or moving components that could cause fatigue-related intermittent breaks.
5
Step 5: If unable to reproduce statically, install a data logger to capture resolver signal data during driving to correlate the intermittent with specific driving conditions.
Estimated Repair Cost
$250 - $2,000
Parts + labor, varies by vehicle and location
DTC P0A49 indicates the drive motor "B" position sensor circuit is experiencing intermittent signal anomalies. The Hybrid Control Module has detected momentary signal dropouts, spikes, or noise bursts in the position sensor data that resolve on their own. These intermittent faults are concerning bec...
The most common cause of P0A49 (Drive Motor "B" Position Sensor Circuit Intermittent) is: Loose or corroded connector terminals at the motor "B" position sensor
Typical repair costs for P0A49 range from $250 to $2,000, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Intermittent position sensor faults can cause momentary torque disturbances during electric drive operation. These may be felt as brief jerks or hesitations. If the fault frequency increases, the HCM may disable motor "B" entirely during a drive cycle.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0A49 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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