Skip the auto shop - Our mechanics make house calls

P0931 OBD-II Trouble Code: Gear Shift Lock Solenoid Circuit High

Check Engine Light

P0931 code definition

The P0931 trouble code detects an issue with the gear shift lock solenoid circuit.

What the P0931 code means

The P0931 code is a generic OBD-II trouble code that notes a voltage reading problem with the gear shift lock solenoid circuit. The gear shift lock solenoid is responsible for making sure that the automatic transmission is unable to move out of the Park position unless the brake pedal is deployed. When the system detects that the brake pedal has been pressed, the gear shift lock solenoid allows the shifter to move from Park into Drive or Reverse. If the powertrain control module (PCM) detects that the voltage reading from the gear shift lock solenoid circuit is abnormally high, then the P0931 code will be stored.

What causes the P0931 code?

A few different things can cause the P0931 trouble code to be triggered:

  • Defective gear shift lock solenoid
  • Defective brake light switch
  • Low battery voltage
  • In rare cases, a defective PCM
  • Damaged electrical components in the circuit, such as wires and connectors

What are the symptoms of the P0931 code?

The P0931 trouble code will usually be accompanied by the Check Engine Light illuminating on the vehicle’s dashboard. The gear shifter will almost always be stuck in Park, so the car cannot be put in gear.

How does a mechanic diagnose the P0931 code?

The P0931 code will be diagnosed using a standard OBD-II trouble code scanner. A trained technician will observe the freeze frame data from the scanner to gather information about the code, and to see if any other trouble codes are present. If multiple different codes are detected, then they should be taken care of in the order that they appear in. The mechanic will then need to clear the trouble codes and restart the vehicle, to see if the P0931 code is still detected. If it is not, then it was either triggered erroneously, or represents an intermittent error.

If the code does remain following the reset, the mechanic will begin with a visual inspection of the system’s electrical components. Any loose or corroded connectors, or open or shorted wires will need to be replaced. The battery should then be checked to make sure that it is properly charged.

Next, the gear shift lock solenoid should be inspected, and tested for continuity. This is the most likely culprit of the P0931 code, but if the solenoid appears to be in working order, then the brake light switch will need to be checked.

After any replacement, the mechanic should pause the inspection and reset the trouble codes and restart the vehicle, to see if the code returns. By doing this, the technician will know as soon as the P0931 code has been resolved.

Common mistakes when diagnosing the P0931 code

The most commonly made mistake when diagnosing the P0931 code is the failure to properly follow the OBD-II trouble code diagnosis protocol. It’s very important that the protocol be followed, as it helps mechanics avoid erroneous repairs. For instance, it is common for the solenoid to be assumed defective, which risks overlooking damaged electrical components and replacing a functioning piece.

How serious is the P0931 code?

A car with the P0931 trouble code will probably not be drivable, because in most cases the vehicle will not be able to shift out of Park. The vehicle will likely require an inspection and repair before it can be driven.

What repairs can fix the P0931 code?

Common fixes for the P0931 trouble code are:

Additional comments for consideration regarding the P0931 code

The P0931 trouble code only applies to vehicles with automatic transmissions. If the car is stuck somewhere and needs to be moved, most transmissions have a fail-safe mechanism built into the shifter, which can be activated with a screwdriver.

Need help with a P0931 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222...
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...


Related questions

Q: Car cut off on the highway and never started back up.

Hello there, many faults will cause your 2004 Chevrolet Impala to die while running and not restart. The P0443 code is for the Evaporative Emission Control System Purge Control Valve Circuit and though this will need to be addressed will...

Q: Car doesn't run after Check Engine light came on

Hi there. When the check engine light starts flashing that means that the engine is experiencing a cylinder misfire. If the engine ended up stalling afterwards then you may have a fuel pump that failed or possibly a timing belt...

Q: P0030 p0015 chk eng lgt on whining noise stuck 2 gear 1 yr had car let son drive 2 NV havent chk fluid N trans hope it wasnt low

The code P0015 is a bank 1 timing over retarded warning. The P0030 code stands for the heated oxygen sensor malfunction, which also pertains to bank 1. The oxygen sensor malfunction could be due to a failed sensor, heater, or...