P0931 — Gear Shift Lock Solenoid/Actuator Control Circuit « A » High

The trouble code P0931 indicates a problem with the control circuit of the gear shift lock solenoid or actuator, specifically that the circuit is reading a high voltage signal when it should not be. This typically affects vehicles with electronic shifters designed to prevent shifting out of park unless certain conditions are met, such as pressing the brake pedal.

It’s important to note that the terminology and labels for this code can vary depending on the manufacturer. Different OEMs may label this malfunction differently in their diagnostic trouble code (DTC) lists, but the underlying issue remains similar.

Fast Facts

System affected: Transmission / Shift Lock System
Severity: Moderate (may prevent shifting out of ‘Park’)
Main symptoms: Difficulty or inability to shift gears, warning lights on dashboard
Driveability: Limited (vehicle may be stuck in park, but engine runs normally)

Manufacturer variations for trouble code P0931

Since different vehicle manufacturers may assign different labels or codes to similar issues, it’s important to recognize these variations to ensure accurate diagnosis and repair. Below are some common manufacturer-specific labels or codes related to this problem:

Ford: U0301 — Gear Shift Lock Circuit Malfunction
Volkswagen / Audi / Skoda / Seat: 08289 — Gear Shift Lock Solenoid Circuit Error
BMW: 00A8 — Gear Selector Lock Control Circuit « A »
Toyota: P2715 — Shift Lock Solenoid Circuit Malfunction
Honda: P shift-related codes, sometimes including manual labels for shift lock circuit issues

What does trouble code P0931 mean?

In simple terms, P0931 signals that the Engine Control Unit (ECU), the vehicle’s computer, has detected an abnormal voltage signal in the gear shift lock solenoid or actuator control circuit. This component ensures that the gear shifter remains locked in Park when the vehicle is off and can only be released under certain conditions, such as pressing the brake pedal.

The code is typically triggered when the ECU reads a voltage level that is higher than expected, indicating a potential short circuit, open circuit, or faulty component in the control wiring. This could happen during normal operation, or as a result of underlying electrical or mechanical issues.

It often appears in the context of attempting to shift gears, or when a driver notices that the shifter is stuck or the vehicle refuses to shift out of Park.

Severity and risks of trouble code P0931

The P0931 code generally poses a moderate risk. Its primary consequence is that it may prevent the driver from shifting out of Park, which effectively immobilizes the vehicle’s transmission. This can be inconvenient or dangerous if it occurs unexpectedly, such as on a busy road or in a hazardous location.

However, the overall impact on safety and drivability can vary depending on the specific vehicle and underlying cause. If the issue is caused by a minor electrical fault, the vehicle can often still be driven once the problem is resolved. Conversely, if it stems from a more serious mechanical defect, further repairs might be necessary.

Conclusion: Limited — the vehicle might be driveable, but in most cases, it cannot be moved out of Park without fixing the fault.

Symptoms of trouble code P0931

The presence of P0931 usually results in certain noticeable symptoms, which can serve as clues during diagnosis. Common symptoms include:

Inability to shift the transmission out of ‘Park’, even when pressing the brake pedal
Warning lights on the dashboard, such as the shift lock warning or transmission warning light
Buzzing or clicking noises from the shift lock solenoid area when attempting to shift
Intermittent shifting issues, especially if electrical connections are loose or corroded
Vehicle remains in ‘Park’ despite attempts to shift to ‘Drive’ or ‘Reverse’

Most likely causes of trouble code P0931

The causes of P0931 are primarily related to electrical faults affecting the shift lock control circuit. While actual causes may differ slightly based on the vehicle, the most common are listed below:

Faulty or sticking shift lock solenoid/actuator: The component responsible for locking and releasing the gear shift may be defective or seized, preventing normal operation.
Wiring issues (short circuits or open circuits):Damaged wiring or connectors in the control circuit can cause abnormal voltage signals, triggering the fault.
Faulty or malfunctioning shift lock control module: Electronic control modules that manage the shift lock mechanism may have internal faults or communication issues.
Low or unstable battery voltage: Insufficient voltage supply can cause erroneous readings in sensor circuits, including the shift lock circuit.
Mechanical obstruction or damage: Physical issues with the shift lock mechanism that prevent the solenoid from functioning properly can also cause the code.

How to diagnose trouble code P0931

Diagnosing P0931 involves a systematic approach to verify the electrical and mechanical condition of the shift lock system. Here are generic steps to guide your process:

Visual inspection: Check all wiring, connectors, and the shift lock solenoid/actuator for signs of damage, corrosion, or disconnection.
Check fuse and relays: Verify that the relevant fuses and relays associated with the shift lock system are intact and functioning correctly.
Test electrical continuity: Using a multimeter, perform continuity and voltage checks on the wiring harness and control circuit to identify open or shorted paths.
Assess battery voltage: Confirm that the vehicle’s battery is sufficiently charged and that power supplies are stable.
Use live data: With a diagnostic scanner, monitor the shift lock actuator circuit while attempting to operate the shift lever, looking for proper signals and responses.
Inspect the shift lock solenoid/actuator: If accessible, test the component directly for correct operation or compare its resistance readings to manufacturer specifications.
Clear the codes and re-test: After repairs or replacements, clear the DTC and verify if the code returns after testing drive cycles.

Possible repairs for trouble code P0931

Depending on the root cause, several repairs may be necessary to resolve P0931. It’s generally advisable to approach these systematically, starting with the simplest fixes:

Replace or repair the shift lock solenoid or actuator: Basic repair, usually handled by a professional if removal from the transmission gear mechanism is required.
Fix wiring issues: Repair or replace damaged cables, connectors, or wiring harnesses. This is a task suitable for a trained technician due to the need for correct electrical diagnostics.
Replace the shift lock control module: If the electronic control unit is faulty, replacing or reprogramming it is necessary. This requires specialized tools and expertise.
Ensure proper electrical connections: Tighten or clean electrical contacts, fuses, and relays associated with the shift lock system.
Address mechanical obstructions: Remove any physically blocking components or repair damage to ensure free movement of the shift lock mechanism.

Remember, some of these repairs require professional intervention, especially those involving electronic modules or significant mechanical disassembly.

Vehicles commonly associated with trouble code P0931 in Europe

While this fault can occur across many makes and models, some vehicle brands are more frequently associated with P0931. Notably, these tend to include vehicles with electronically controlled shifters or modern transmission control systems:

Ford: Focus, Fiesta, Kuga, Mondeo
Volkswagen Group: Golf, Passat, Polo, Skoda Octavia, Audi A3
BMW: 1 Series, 3 Series, X Series
Toyota: Corolla, Yaris, RAV4
Honda: Civic, CR-V, Jazz

In Europe, these vehicles often share similar transmission control architectures, making them more prone to related control circuit faults.

Frequent mistakes with trouble code P0931

Diagnosing and repairing P0931 can sometimes lead to common pitfalls. Awareness of these can ensure a more efficient and accurate repair process:

Overlooking wiring integrity: Assuming the fault is always with the solenoid or module while ignoring wiring damage or corrosion.
Replacing components without proper testing: Installing new parts without verifying the actual cause, leading to unnecessary expenses.
Ignoring related electrical issues: Failing to check battery voltage, fuses, or relays that may be contributing to the problem.
Misdiagnosing mechanical faults as electrical: Failing to inspect physical damage or obstructions in the shift lock mechanism.
Neglecting to clear DTC after repairs: Not erasing stored codes and confirming faults have been resolved, leading to confusion and repeat diagnoses.

Quick FAQ — trouble code P0931

Can this code disappear on its own?

Generally, P0931 does not resolve spontaneously. It is triggered by a persistent electrical or mechanical fault. If the underlying issue is fixed, the code can be cleared manually, but it won’t disappear unless the problem is addressed.

Can I keep driving?

In most cases, driving is limited. The vehicle may be stuck in Park, especially if the control circuit or solenoid is faulty. Attempting to force shift or ignore the warning can damage other components or create safety issues. It’s best to diagnose and repair the problem promptly.

Why does the code return after clearing it?

The code P0931 returns when the fundamental fault, such as wiring damage, a malfunctioning solenoid, or control module issue, remains unresolved. Consistently recurring codes indicate the need for a thorough inspection and targeted repairs.