P0A49: Drive Motor B Position Sensor Circuit Intermittent

P0A49 covers short dropouts or jumps in the motor B resolver signal that are too brief to count as a lasting loss, low or high fault. No manufacturer documents this code publicly. The motor A twin P0A43 is used by Stellantis on the Pacifica Hybrid, where dealers must check bulletins and reflash the hybrid control processor before replacing the power inverter module. GM shows on the Bolt that a slightly spread resolver terminal can cause brief signal loss and a sudden loss of drive, and forbids splicing resolver connectors because the circuits are sensitive. CARB 1968.2 requires detection of intermittent circuit faults of drive components. P0A45 is the permanent fault. Expect a warning that may clear after a restart.

Symptoms

• Hybrid warning or MIL that comes and goes
• Brief loss of second-motor drive, often over bumps
• Code stored as history without current symptoms

Most likely causes

• Loose or spread terminal in the motor B resolver connector
• Chafed or stretched resolver wiring near the rear axle or subframe
• Moisture in the connector causing intermittent leakage
• Hybrid control software needing an update

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes with a hybrid-compatible scanner and write down the freeze frame data
2. Gently move the wiring with the engine running and watch whether the reading changes.
3. Make sure the battery cooling air intake is clean
4. Check the 12 V auxiliary battery, which can also trigger warnings
5. Leave any high-voltage measurements to a specialized repair shop

Good to know

• It can trigger limp mode.
• It affects emissions.

What each character of P0A49 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• A: Hybrid or air and fuel
• 49: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0A49?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0A49?

The most common causes are: loose or spread terminal in the motor B resolver connector; chafed or stretched resolver wiring near the rear axle or subframe; moisture in the connector causing intermittent leakage.

Related codes

• P0A45Drive Motor B Position Sensor Circuit
• P0A46Drive Motor B Position Sensor Circuit Range/Performance
• P0A47Drive Motor B Position Sensor Circuit Low
• P0A48Drive Motor B Position Sensor Circuit High
• P0A43Drive Motor A Position Sensor Circuit Intermittent

Sources

• law.cornell.edu: 13 CCR 1968.2
• static.nhtsa.gov: MC 11031463 0001
• static.nhtsa.gov: MC 10232147 0001

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.