P0931 — Gear Shift Lock Solenoid/Actuator Control Circuit “A” High #

Code meaning may vary depending on manufacturer.

Known label variations:

• Shift Lock Solenoid Circuit High (Honda)
• Gear Shift Interlock Actuator “A” Control Circuit High (Toyota)
• Shift Lock Solenoid Control High (GM/Chevrolet)

Summary of DTC P0931 #

DTC P0931 indicates a detected abnormal voltage condition in the gear shift lock solenoid/actuator control circuit “A”. This circuit manages the solenoid or actuator responsible for keeping the gear shifter locked in position until certain conditions are met, such as pressing the brake pedal. The “High” descriptor means the Powertrain Control Module (PCM) or Transmission Control Module (TCM) has seen a voltage reading above the expected range for this circuit. This fault is a safety-related alert, as the shift lock system prevents unintended gear changes. Depending on the vehicle, this code may impact the ability to shift out of Park or cause warning lights to appear.

Frequent Symptoms for DTC P0931 #

When P0931 is active, drivers and technicians may notice a range of symptoms linked to the gear shift lock mechanism. These can present as both mechanical and electrical issues, often showing up during attempts to move the gear selector or as warning signals on the dashboard.

• Unable to shift out of “Park” position
• Gear lever feels stuck or unusually firm
• Intermittent or delayed gear engagement
• Illuminated “Check Engine” or transmission warning light
• Brake lights not working when pressing the pedal (in some cases)
• Audible clicking from the shifter area

Probable Causes for DTC P0931 (from most to least common) #

The root causes of P0931 usually relate to electrical or mechanical faults within the shift lock system. Some issues stem from wear and tear, while others may be due to wiring or component failure. Understanding the order of likelihood helps target diagnostics efficiently:

1. Faulty shift lock solenoid/actuator (internal short or coil failure)
2. Short to voltage in control circuit wiring (damaged insulation, pinched wires)
3. Defective brake pedal switch (improper signal to solenoid circuit)
4. Poor electrical ground connection (corroded or loose ground points)
5. Faulty PCM/TCM output (rare, but possible in case of module failure)
6. Aftermarket accessories spliced into shifter wiring (e.g., remote start, alarms)

Step-by-step Diagnostic for DTC P0931 #

Diagnosing P0931 requires a systematic approach to isolate the cause of the high circuit reading. Using a digital multimeter and a scan tool, follow these steps to pinpoint the fault efficiently:

• Confirm code and freeze frame data with a scan tool; clear and see if returns.
• Visually inspect shift lock solenoid/actuator and related wiring for damage or corrosion.
• Check the control circuit (“A”) voltage at the solenoid connector with ignition ON (should match OEM specs).
• Test resistance of the shift lock solenoid coil (compare to OEM values).
• Test for shorts to voltage in wiring between the PCM/TCM and solenoid connector.
• Inspect and test the brake pedal switch function and signal output.
• Check all related fuses and grounds for integrity and cleanliness.
• If all wiring and components check out, consider PCM/TCM output function (consult OEM procedures).

Possible Repairs for DTC P0931 #

Based on what the diagnosis reveals, repairs may range from simple wire fixes to component replacement. Each repair should address the underlying electrical or mechanical fault to prevent recurrence.

• Replace faulty shift lock solenoid/actuator
• Repair or replace shorted or damaged wiring in control circuit “A”
• Replace defective brake pedal switch
• Clean and secure ground connections
• Remove or rewire aftermarket accessories interfering with shift lock wiring
• In rare cases, replace the PCM/TCM if verified to be faulty

Can You Drive with Code P0931? #

Driving with P0931 is generally limited or not recommended. If the gear shift lock system is malfunctioning, you may not be able to shift out of Park, which effectively immobilizes the vehicle. In some cases, you might be able to use a manual release to drive temporarily, but the risk of unintended gear engagement or inability to shift remains. For safety and to prevent further electrical issues, address the fault promptly before regular use.

Vehicles Most Commonly Affected by DTC P0931 #

While P0931 can appear on any vehicle with an electronically controlled shift lock system, it’s most frequently reported on models from certain manufacturers. This is often due to design or part sourcing choices.

• Honda/Acura (Civic, Accord, CR-V, Odyssey)
• Toyota/Lexus (Camry, Corolla, RAV4, ES350)
• Chevrolet/GM (Malibu, Equinox, Silverado, Traverse)
• Hyundai/Kia (Sonata, Elantra, Sorento)
• Nissan/Infiniti (Altima, Maxima, Rogue, QX60)

Frequent Mistakes & Best Practices for DTC P0931 #

Many DIYers and even some technicians make avoidable errors when troubleshooting P0931. Staying methodical and aware of these common pitfalls can save time and prevent repeat repairs.

• Assuming the shifter assembly is always at fault—wiring and switches are often the real culprits.
• Overlooking aftermarket accessory wiring that may have been spliced into shift lock circuits.
• Neglecting to test the brake pedal switch thoroughly—its signal is critical for shift lock operation.
• Replacing the shift lock solenoid without confirming circuit voltage and ground integrity.
• Skipping a visual inspection for corrosion or liquid spills near the center console/shifter area.

Quick FAQ for DTC P0931 #

Drivers and technicians often have urgent questions when faced with a gear shift lock fault like P0931. Here are some fast answers:

• Q: Can I use the manual shift lock release to drive if P0931 is active?
  A: Yes, most vehicles have an emergency shift lock override, but this is for temporary use only. The root cause should be repaired as soon as possible.
• Q: Will clearing the code make the gear shifter work again?
  A: Simply clearing the code rarely solves the problem. The underlying electrical or mechanical fault must be fixed to restore proper shifter function and prevent the code from returning.