P0A3F Drive motor A rotor position sensor circuit fault

Drive motor A position sensor 1 circuit

P0A3F in short

P0A3F means the computer is not getting a good signal from the position sensor on drive motor A. Bulletins link it to loose or damaged connectors, software, a failed inverter or a fault inside the motor and transmission assembly. Loss of power or a stall is possible, and the parts involved are high voltage.

An electric drive motor needs to know exactly where its rotor is so the inverter can time the current. A sensor on the motor, usually a resolver, reports that position. If the signal is missing, noisy or does not make sense, the computer sets P0A3F.

The bulletins differ by make. Ram traced it to a motor generator connector not fully seated. GM told dealers on the Bolt EV to check connections first and, if nothing is found, replace the inverter, harness and transmission. Chrysler has software updates and a warranty extension for a transmission wiring connector short on the Pacifica. Honda ties it to a faulty inverter solder joint.

The motor, inverter and cables carry high voltage. Nothing here asks you to open them. Reading codes and asking about bulletins are safe; the rest is for a technician.

Most likely causes

  1. Loose or damaged connector or wiring at the motor position sensor circuit

    Supported by vehicle data
    Why it ranks here
    Ram replaces the motor generator unit when its connector is not fully seated, and GM says to check connections first on the Bolt EV before replacing parts.
    What would change this
    Rises if the fault is intermittent and comes with P1B03 (resolver signal) or U0594. Falls if the connectors test fine.
    How to test the hybrid drive motor

  2. Hybrid control software (Pacifica Plug-in Hybrid)

    Supported by vehicle data
    Why it ranks here
    Chrysler bulletin 08-044-17 reprograms the hybrid control processors for a list that includes P0A3F, and bulletin 9100801 says to check those flashes before ordering an inverter. Subaru also has a reprogramming file bulletin naming P0A3F on the 2014 Crosstrek Hybrid.
    What would change this
    Rises if updates are open for the VIN. Falls if the software is current and the code returns.

  3. Failed power inverter module (high voltage)

    Supported by vehicle data
    Why it ranks here
    Honda extends coverage on the Civic Hybrid motor power inverter for a solder joint failure that can set P0A3F, and GM lists replacing the Bolt EV power inverter module if connections check out.
    What would change this
    Rises if connectors and software are ruled out. Falls if the position sensor circuit tests fault only at the motor.

  4. Internal wiring or bearing fault in the drive motor and transmission assembly

    Supported by vehicle data
    Why it ranks here
    Chrysler has warranty extensions for an internal transmission wiring connector short and a motor A bearing failure on Pacifica Plug-in Hybrid and Voyager, with a record that mentions this code; only the summary was read.
    What would change this
    Rises on a Pacifica or Voyager built 2017-2023 once software is ruled out. Falls on other models.
    How to test the hybrid drive motor

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all stored codes from every module and note the ones that sit with P0A3F, such as P1B03, P0A78 or U0594.

    Low riskTool: OBD-II scan tool that reads hybrid modules

  2. Ask a dealer whether your VIN has an open software update, warranty extension or recall for P0A3F.

    Low risk

  3. Have a technician trained in high-voltage systems test the position sensor circuit and connections at the drive motor and inverter.

    Best left to a shopTool: manufacturer scan tool, high-voltage safety equipment

    Warning:The inverter, motor and orange cables are high voltage and can cause fatal shock. Do not open or test them yourself.

Symptoms

  • Check engine light or a hybrid system warning
  • Loss of propulsion that clears after a restart (Bolt EV)
  • Hesitation, limp mode or reduced power
  • Stall with no restart, or a no-start Gets more serious: stop and have it checked.

Compare with: Check engine light with loss of power

How to fix

This is a safety-critical system, so we explain the code but don't give repair steps. Have it inspected by a qualified technician.

Parts and cost context

  • Hybrid drive motor:High-voltage part. Check software updates and the maker's warranty extensions for your VIN before paying; Chrysler and Honda both extend coverage for some failures. Labour varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Chevrolet

  • 2017–2020 · Bolt EV

    Supported by vehicle data

    GM preliminary bulletin PIP5641 (revisions to D) says engineering was investigating P0A3F; check connections first, then replace the inverter, harness and transmission if nothing is found. Status not verified.

  • 2016–2018 · Volt

    Supported by vehicle data

    GM bulletin 18NA186 covers loss of propulsion or no start with P0A3F or P1B03 on the Volt (and Malibu). Status not verified.

  • PIP5641Status unverified

    Engineering investigating P0A3F

    2017–2018bolt-ev · NHTSA 10160685

    Check connections; if nothing is found, replace the power inverter module, the under-hood harness and the transmission. Later revisions (A to D, NHTSA 10162117 to 10170434) extend the years to 2020.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 18NA186Status unverified

    Loss of propulsion or no start with MIL and P0A3F or P1B03

    2016–2018volt · NHTSA 10166648

    Diagnostic information for these two codes; the NHTSA summary does not give the repair.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Chrysler

  • 2017–2025 · Pacifica

    Supported by vehicle data

    Chrysler lists P0A3F with hybrid control software flashes on the Pacifica Plug-in Hybrid and a warranty extension for an internal transmission wiring connector short. Status not verified.

  • 2020–2025 · Voyager

    Supported by vehicle data

    Chrysler 9100801 covers Voyager with the Pacifica list: check hybrid control flashes before ordering an inverter. Status not verified.

  • 08-044-17Status unverified

    Hybrid control processor and auxiliary processor flash

    2017pacifica · NHTSA 10224727

    Reprogram both processors when the MIL is on with codes including P0A3F, P0A78 and P0A79.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 9100801Status unverified

    Check hybrid control flashes before ordering an inverter

    2019–2025pacifica, voyager · NHTSA 11031463

    If P0A78, P0A79 or P0A3F-00 are present, check the active software bulletins before ordering a power inverter module.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 21-042-24Status unverified

    Internal transmission wiring connector short and motor A bearing failure warranty extension

    2017–2023pacifica · NHTSA 11001830

    Warranty extension on the Pacifica Plug-in Hybrid for customers with the MIL on and listed codes; the record text mentions P0A3F.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Ram

  • 2020–2021 · 1500

    Supported by vehicle data

    Ram bulletin 08-014-21 replaces the motor generator unit when its connector is not fully seated, with P0A3F-00 among the codes. Status not verified.

  • 08-014-21Status unverified

    Motor generator unit connector not fully seated

    2020–20211500 · NHTSA 10187133

    Replace the motor generator unit; codes include P0A3F-00 and P1B03-00, with a stall after 15-40 minutes of driving.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Honda

  • 2012–2015 · Civic

    Supported by vehicle data

    Honda extends inverter coverage on the Civic Hybrid for a solder joint failure that can set P0A3F. Status not verified.

  • A20-030Status unverified

    Motor power inverter solder joint failure

    2012–2015civic · NHTSA 10184658

    A defective solder joint can fail the inverter and set several codes including P0A3F; coverage extended to 15 years or 150,000 miles.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Acura

  • B20-021Status unverified

    Motor power inverter solder joint failure

    2013ilx · NHTSA 10184664

    Acura ILX Hybrid version of Honda A20-030.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Subaru

  • 2014 · XV CrossTrek

    Supported by vehicle data

    Subaru has a reprogramming file for P0CDD and P0A3F on the 2014 Crosstrek Hybrid. Status not verified.

  • 07-82-14RStatus unverified

    Reprogramming file availability for P0CDD and P0A3F

    2014xv-crosstrek · NHTSA 10068306

    A reprogramming file is available for the Crosstrek Hybrid for these two codes.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • P0A78The inverter that powers hybrid drive motor A is not performing as expected

    Shares causes Supported by vehicle data

    Chrysler bulletin 08-044-17 lists P0A78 and P0A3F together for one hybrid control software update on the 2017 Pacifica Plug-in Hybrid.

  • P0A43Hybrid drive motor A position sensor signal cutting in and out

    Same system Possible — needs testing

    Both are drive motor position sensor codes, and Chrysler 9100801 lists them with P0A78 under one rule: check software flashes before ordering an inverter. P0A43 is the intermittent-signal variant.

All Hybrid and electric drive codes

P0A3F questions

Should I replace the inverter for P0A3F?

Not first. Bulletins point to connectors and software before the inverter, and some makers extend coverage. A technician should test the circuit.

Sources and review

  1. Ram 08-014-21 (NHTSA 10187133) — FCA / Ram
  2. GM 18NA186 (NHTSA 10166648) — General Motors
  3. GM PIP5641 to PIP5641D (NHTSA 10160685 to 10170434) — General Motors
  4. Chrysler 08-044-17 (NHTSA 10224727) — FCA / Chrysler
  5. Chrysler 9100801 (NHTSA 11031463) — FCA / Chrysler
  6. Subaru 07-82-14R (NHTSA 10068306) — Subaru of America
  7. Honda A20-030 (NHTSA 10184658) — American Honda
  8. Chrysler 21-042-24 (NHTSA 11001830) — FCA / Chrysler
Last reviewed
Written by
Saurabh K.
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