P1437 On Honda hybrids, a short circuit in the motor power inverter module

Honda MPI module short circuit (Motor Drive Module)

P1437 in short

On Honda hybrids, P1437 means a short circuit in the motor power inverter module. Honda bulletin A20-030 lists it among the codes caused by a defective solder joint in the inverter on the 2012-2015 Civic Hybrid, with warranty extended to 15 years or 150,000 miles. Get it checked soon; stop if power drops.

The motor power inverter switches the hybrid battery's direct current into the form the electric motor needs. P1437 is Honda's code for a short circuit in that module. Other makers use P1437 for different things, so this page speaks only for Honda.

Honda bulletin A20-030 says a defective solder joint can make the inverter fail over time, and lists P1437 with P1440, P15A5, P0A78, P0AE1, P0A3C, P0A3F, P0DA8, P1634, P0AEE and P0A27. Honda extended the inverter warranty to 15 years or 150,000 miles. Acura issued B20-021 for the 2013 ILX Hybrid with the same list.

Three owner complaints we read store P1437 on a 2012 and a 2013 Civic Hybrid and a 2013 ILX Hybrid: stalling in an intersection, a no-restart and locked power steering. Two were told their VIN was not on the bulletin list, so coverage depends on the VIN.

The inverter is high-voltage. Owners should not touch the orange cables or open the inverter; diagnosis belongs with a dealer.

Pick your make

P1437 is a manufacturer-specific code: its meaning depends on who built the car.

Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.

Most likely causes

  1. Failed motor power inverter from a defective solder joint

    Supported by vehicle data
    Why it ranks here
    Honda bulletin A20-030 and Acura B20-021 list P1437 among the codes from this defect and extend coverage; three owners store the code on covered models.
    What would change this
    Rises if P1440, P15A5 or P0A78 are stored with it on a 2012-2015 Civic Hybrid or 2013 ILX Hybrid. Falls if the VIN is outside the bulletin and no other inverter codes are stored.
    How to test the hybrid drive motor

  2. Other inverter or wiring fault

    Possible — needs testing
    Why it ranks here
    Owners with VINs outside the bulletin store the same code, which means a fault outside the covered production range is possible.
    What would change this
    Rises if the inverter fails the maker's tests despite no bulletin match. Falls if the inverter passes.

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 with a scan tool and write down the dashboard messages. Do not open or unplug anything in the hybrid system.

    Low riskTool: OBD-II scan tool

    • IfP1437 is stored on a 2012-2015 Civic Hybrid or 2013 ILX Hybrid

      It meansHonda's inverter coverage may apply.

      Go to step 2

    • IfIt is stored on another Honda or Acura model

      It meansThe maker's diagnosis decides.

      Go to step 3

  2. Give the VIN to a Honda or Acura dealer and ask if the inverter extended warranty applies.

    Low riskTool: VIN lookup at a dealer

  3. Have a dealer or hybrid-trained technician run the inverter diagnostics from Honda's service information.

    Best left to a shopTool: factory scan tool and high-voltage safety equipment

    Warning:High voltage: the battery pack, inverter, motors and orange cables carry hundreds of volts that can kill. Do not unplug, probe or touch them. This work needs a hybrid-trained technician who makes the system safe first.

Symptoms

  • IMA, check charging system or check brake system messages
  • Stalling or no restart Gets more serious: stop and have it checked.
  • Power steering locks up after power loss 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

  • Motor power inverter (Honda, Acura hybrids):High-voltage part. Honda extended coverage to 15 years or 150,000 miles for listed VINs; check before paying. Labor 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

Honda

  • 2012–2015 · Civic

    Supported by vehicle data

    Civic Hybrid: Honda extended inverter coverage; owners with P1437 stalled in traffic and two were told the VIN was not on the bulletin.

  • A20-030Status unverified

    Motor power inverter warranty extension (Civic Hybrid)

    2012–2015civic · issued · NHTSA 10184658

    Defective inverter solder joint can set P1440, P1437, P15A5, P0A78, P0AE1 and other codes; 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

  • 2013 · ILX

    Supported by vehicle data

    ILX Hybrid: Acura bulletin B20-021 carries the same code list; an owner lost restart and power steering with P1437 and P15A5.

  • B20-021Status unverified

    Motor power inverter warranty extension (ILX Hybrid)

    2013ilx · issued · NHTSA 10184664

    Same as A20-030 for the 2013 ILX Hybrid.

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

  • P0AE1A fault in the hybrid battery precharge contactor circuit; Honda lists it as a bypass contactor fault

    Shares causes Supported by vehicle data

    Honda bulletin A20-030 lists P1437 and P0AE1 among codes from the same inverter solder joint fault.

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

    Shares causes Supported by vehicle data

    An owner readout lists P1437 with P0A78 on a 2012 Civic Hybrid, and Honda lists both in A20-030.

All Hybrid and electric drive codes

P1437 questions

What does P1437 mean on a Honda?

Honda lists it as a short circuit in the motor power inverter module, among the codes from a defective inverter solder joint on the Civic Hybrid.

Is the inverter covered on my Civic Hybrid?

Possibly. Honda extended inverter coverage on the 2012-2015 Civic Hybrid to 15 years or 150,000 miles for listed VINs. A dealer can check yours.

Sources and review

  1. A20-030: motor power inverter warranty extension (Civic Hybrid) — American Honda
  2. NHTSA complaint ODI 2152043: 2013 Honda Civic Hybrid — NHTSA Office of Defects Investigation
  3. NHTSA complaint ODI 1995972: 2013 Acura ILX Hybrid — NHTSA Office of Defects Investigation
  4. B20-021: motor power inverter warranty extension (ILX Hybrid) — American Honda (Acura)
  5. NHTSA complaint ODI 2096927: 2012 Honda Civic Hybrid — NHTSA Office of Defects Investigation
Last reviewed
Written by
Saurabh K.
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