P0931Generic code

P0931 Code: Gear Shift Lock Solenoid Control Circuit High

The P0931 code means the shift lock solenoid control circuit is reading high voltage, either an open circuit or a short to voltage. The shifter may not come out of Park. Check the connector, the wiring, the fuse and the relay before you replace the solenoid.

Severity
Medium
Can I keep driving?
Yes, but with caution
Estimated cost
$40 to $400
Difficulty
Medium
System
Transmission
Applies to
All OBD2 vehicles

Updated Reviewed by Renzo Chacca

On this page

What the P0931 code means

The shift lock solenoid keeps the lever from moving out of Park (or the shift mechanism from moving) unless the safety conditions are met, normally with the brake pedal pressed.

The computer monitors the control circuit through its own driver transistor. The P0931 code is set when the circuit shows high voltage, usually an open circuit or a short to voltage. Before you replace the component, check the fuse, relay, connector and wiring, because those are the most common causes.

If it fails, the lever may not come out of Park, or it may not lock at all. Many shifters have a manual emergency release. After any repair of these components you must run the transmission relearn procedures with a scan tool (clutch touch point, select and shift positions). Without them the transmission will not work properly.

To confirm the fault, measure the continuity of each wire between the component connector and the computer connector with the key off. It should be under 1 ohm, and an infinite reading means the wire is open. If the wiring is good, measure the component itself. An infinite resistance confirms it is open inside.

P0931 code symptoms

  • Check engine light or another warning light on.
  • The shifter will not come out of Park.
  • The transmission does not engage gears or stays in neutral.
  • Transmission or engine warning light on.
  • Beep or warning message in the instrument cluster.

Likely causes of the P0931 code

  1. Loose or broken connector. The most frequent cause, especially right after another repair.
  2. Open coil or motor. The resistance reads infinite.
  3. Cut control wire between the component and the computer.
  4. Short to 12 volts. The control wire touches another wire that carries voltage.

How to diagnose the P0931 code step by step

  1. Command the component with the scan tool and check whether it responds.
  2. Check the fuse and the relay. Measure voltage on both sides of the fuse, and swap the relay with an identical one.
  3. Measure the supply at the connector. You should see battery voltage with the key on or when the component is commanded.
  4. Measure the resistance of the component and compare it with the manual. Also check its insulation to ground.
  5. Check the control wire. Confirm continuity all the way to the computer and make sure there is no short.
  6. Activate the actuator with the scan tool and see whether it moves.
  7. Run the transmission relearn procedures after any repair.
  8. Measure battery voltage during activation. It should not fall below 11 volts.

How to fix the P0931 code

  • Repair the connector, the wiring or the power supply.
  • Replace the shift lock solenoid if it does not respond even with correct power and control signals.
  • Clear the codes and verify the repair.

Technical reference data

  • Electric actuator (DC motor) or a hydraulic solenoid valve controlled by a PWM signal.
  • Wire continuity between connectors: below 1 ohm.
  • Minimum battery voltage during activation: about 11 volts.
  • Approximate values only: check the manufacturer data for your vehicle.

Brand-specific notes

This code is very common on automated manual transmissions. On many hydraulic systems the actuator fluid is a specific type and the reservoir should be checked regularly.

P0931 on Opel

Very common on the Opel Easytronic.

P0931 on Fiat

Very common on the Fiat Dualogic.

P0931 on Toyota

Very common on the Toyota MMT.

P0931 on Smart

Seen on Smart vehicles with an automated manual transmission.

P0931 on BMW

Very common on the BMW SMG.

Frequently asked questions about P0931

Can I drive with a P0931 code?
Only with caution and only as far as the shop. The transmission can lose its gears at any moment.
What does the shift lock solenoid do?
It keeps the lever from moving out of Park, or the shift mechanism from moving, unless the safety conditions are met, normally with the brake pedal pressed.
Do I always have to replace the part?
No. Check the fuses, relays, connectors and wiring first. They are the usual causes and cost much less than a new solenoid.
How much does it cost to fix P0931?
As a rough guide, between $40 and $400. A connector or wire repair is cheap, while a solenoid replacement costs more.
What does the P0931 code mean?
The P0931 code is a generic OBD2 code that means the shift lock solenoid control circuit is reading high voltage, which points to an open circuit or a short to voltage.
Will a P0931 code clear itself?
Only if the cause was a temporary glitch. A loose connector or an open wire will bring it back.
What is the most common cause of P0931?
A loose or broken connector, especially after another repair. An open solenoid and a cut control wire follow.

Related codes

Questions about the P0931 code

There are no questions about this code yet. Tell us about your case: vehicle, symptoms and what you have already checked.