The P0927 error code indicates that the Engine Control Module (ECM) has detected a problem in the operation of the transmission gear shift reverse actuator. The gear shift reverse actuator controls how a vehicle’s transmission shifts into reverse.

What does the P0927 code mean?

In simple terms, the OBD-II fault code P0927 means that the ECM has found a signal indicating that the voltage in the gear shift reverse actuator was above normal parameters.

This voltage anomaly can be caused by a malfunction of the guide rail or the shift shaft corresponding to reverse gear in the transmission, making it difficult or impossible to shift into reverse.

What causes the P0927 code?

Although several issues can trigger a higher-than-normal reading in the reverse actuator circuit, causing the Check Engine light to illuminate on a vehicle’s dashboard, the cause of the code is likely due to a mechanical problem in the transmission.

What are the symptoms of the P0927 code?

• When the P0927 code causes the Check Engine light to come on, the following symptoms may be present:
•     Difficulty or inability to shift into reverse
•     Reduced energy efficiency

How does a mechanic diagnose the P0927 code?

A certified technician must first verify the existence of the P0927 code with a specialized scan tool before proceeding further. Several scans may be necessary to determine if the problem is intermittent or constant, along with other tests, including a visual inspection.

Common mistakes when diagnosing the P0927 code

After recording the P0927 code, a technician may make the following errors:

    Not checking that the voltage through the gear shift reverse actuator is high
    Failing to visually inspect the transmission, especially components related to reverse gear
    Forgetting to clear the OBD-II P0927 error code once the problem is resolved

How severe is the P0927 code?

A vehicle registering the P0927 code may still be drivable, although it may not shift into reverse easily or at all. Over time, this issue can affect the operation of other parts and systems, so it is advisable to promptly contact a qualified mechanic for assistance in diagnosing and repairing the root cause of the P0927 code being recorded.

What repairs can fix the P0927 code?

• After a qualified mechanic has used a specialized scan tool to verify the existence of the P0927 code, the vehicle may need the following repairs:
•     Adjustment of the guide rail or shift shaft corresponding to reverse gear
•     Replacement of the entire transmission
•     Replacement of the ECM in rare cases

To prevent an unintentional rollback situation, modern vehicles are equipped with what is called a gearshift lock solenoid. When the computer detects that all conditions are met (foot on the brake pedal, gearshift lever lock button pressed) to safely move the vehicle out of park, the gearshift lock solenoid releases and allows the transmission to shift into gear. A DTC P0928 means there is an electrical issue in the control circuit of this solenoid.

How severe is the code?

Obviously, a diagnostic code P0928 is quite serious, as it likely means you will not be able to drive your vehicle.

Symptoms

Symptoms of a P0928 include:

    Transmission cannot shift out of park

Causes

•     Low or dirty transmission fluid
•     Low battery voltage
•     Bad fuse(s) or fuse link(s)
•     Damaged wiring or connectors
•     Gearshift lock solenoid
•     Faulty brake light switch

How to diagnose the code?

Diagnosing an OBDII P0928 fault code should begin with a thorough inspection of the wiring and connectors related to the gearshift lock solenoid (there may be a short circuit or liquid damage if something was spilled around the gearshift lever). Battery voltage, fuses, fuse links, and relays should also be tested. The brake light switch must also be considered, along with the condition of the transmission fluid.

What repairs will fix P0928?

•     Change transmission fluid/filter
•     Charge or replace the battery
•     Replace any blown fuse or fuse link
•     Replace any damaged wiring or connector
•     Replace the gearshift lock solenoid
•     Replace the brake light switch

Definition of Code P0929

Code P0929 is a generic powertrain code related to the transmission, including pressure faults and sensor failures. In this case, the transmission control module has detected a fault in the shift lock solenoid circuit.

What does code P0929 mean?

A vehicle with an automatic transmission uses the shift lock solenoid to ensure that your vehicle cannot be moved out of “Park” without the brake pedal being pressed. When the vehicle’s engine is “on” and the brake pedal is fully depressed, the shift lock solenoid allows the vehicle to shift from “Park” to “Reverse” or “Drive”.
When the engine control module (ECM) detects an abnormal voltage reading or signal from the shift lock solenoid, a code P0929 may be stored.

What causes code P0929?

Several issues can cause a code P0929, including:

• Low transmission fluid
• Dirty transmission fluid
• Low battery voltage
• Damaged or corroded electrical wiring to or from the shift lock solenoid
• Damaged or faulty shift lock solenoid
• Damaged or faulty brake light switch
• Damaged or faulty ECM (rare)

What are the symptoms of code P0929?

Symptoms of a code P0929 may include:

• Check engine or warning light may illuminate
• The vehicle will not shift out of park

How does a mechanic diagnose code P0929?

A mechanic may use several methods to diagnose a P0929 fault code, including:

• Using an OBD-II scanner to check for a stored P0929 fault code
• Checking the transmission fluid level
• Checking the quality of the transmission fluid
• If the transmission fluid is dirty, check the transmission pan for signs of clutch debris or other contaminants
• Checking battery voltage/charge
• Visually inspecting wiring and the electrical system for any obvious signs of damage or wear
• Checking for blown fuses
• Testing the shift lock solenoid for continuity
• Testing the brake light switch for continuity

Common mistakes when diagnosing code P0929

A common cause of a P0929 fault code is a faulty brake light switch, which will not allow the vehicle to shift out of park. The fuse that controls the brake light switch and shift lock may have blown and should be diagnosed before performing any further repairs or replacements.

How severe is code P0929?

Since safely operating a vehicle will most likely be affected due to faults that store a P0929 code, this code is considered a potentially serious one. When this code appears, it is recommended to bring your vehicle to your local service center or a mechanic immediately for repair and diagnosis.

What repairs can fix code P0929?

Several repairs can correct a P0929 fault code and include:

• Fill transmission fluid to manufacturer-recommended levels
• Change transmission fluid (if necessary)
• Charge or replace the vehicle battery
• Replace any damaged or blown fuses
• Repair or replace the damaged or faulty brake light switch
• Repair or replace the damaged or faulty shift lock solenoid
• Clear all codes, test the vehicle, and rescan to see if any codes reappear

P092A Possible Causes

• Faulty gear shift lock solenoid
• Gear shift lock solenoid wiring harness open or shorted
• Poor electrical connection in gear shift lock solenoid circuit

What Does It Mean?

First diagnose the P092A code

Check the “Possible Causes” listed above. Visually inspect related wiring harnesses and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P092A Possible Symptoms

Check engine light illuminated (or service engine soon warning light)

P092A Description

The Transmission Control Module (TCM) monitors the gear shift lock solenoid. The TCM sets the OBDII code when the gear shift lock solenoid does not meet factory specifications.

P092B Possible Causes

    Faulty gear shift lock solenoid
    Gear shift lock solenoid harness is open or shorted
    Poor electrical connection in gear shift lock solenoid circuit

 

What Does It Mean?

First diagnose code P092B

    Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P092B

Possible Symptoms

    Check engine light illuminated (or service engine soon warning light)

P092B Description

The Transmission Control Module (TCM) monitors the gear shift lock solenoid. The TCM sets the OBDII code when the gear shift lock solenoid does not meet factory specifications.
OBDII Code P092B – Gear Shift Lock Solenoid/Actuator Control Circuit Range/Performance

Introduction

Error code P092C is an OBD-II code that indicates a problem with the shift lock solenoid or actuator “B” control circuit. This issue is typically caused by a detected low voltage in the circuit, which can prevent smooth gear shifting.

Possible Causes

Several factors can cause the P092C code:

• Faulty shift lock solenoid or actuator
• Damaged or short-circuited wiring harness
• Corroded or improperly connected connector
• Problem with the Transmission Control Module (TCM)

Symptoms

Symptoms associated with code P092C include:

• Difficulty shifting into certain gears
• Irregular or delayed gear shifting
• Illumination of the check engine light
• Activation of limp mode preventing certain gear shifts

Diagnosis and Repair

1. Visual Inspection: Check connectors and wiring for any damage or improper connections.
2. Solenoid/Actuator Testing: Use a multimeter to measure the component’s voltage and resistance to verify proper operation.
3. Electrical Circuit Check: Verify the solenoid’s supply voltage and look for any electrical anomalies.
4. Replacement of Faulty Components: If the solenoid, wiring harness, or control module is defective, replace it according to manufacturer recommendations.

Conclusion

Codes P2009 and P092C indicate problems affecting engine and transmission performance. Thorough inspection and accurate diagnosis help identify and resolve these issues to ensure proper vehicle operation.

P092D Possible Causes

• Faulty gear shift lock solenoid
• Gear shift lock solenoid harness is open or shorted
• Poor electrical connection in the gear shift lock solenoid circuit

What Does It Mean?

How to Fix Code P092D

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

P092D Possible Symptoms

Check engine light illuminated (or service engine soon warning light)

P092D Meaning

The Transmission Control Module (TCM) monitors the gear shift lock solenoid. The TCM sets the OBDII code when the gear shift lock solenoid does not meet factory specifications.

P092E, P092F ISO/SAE reserved

Definition of Fault Code P0930

A fault code P0930 is related to a vehicle’s automatic transmission and its shift lock solenoid, which prevents the gear lever from being moved out of park without the brake pedal being pressed.

What Does Code P0930 Mean?

P0930 is a generic OBD-II powertrain code for a low voltage issue with the shift lock solenoid, indicating that the Powertrain Control Module (PCM) does not believe the brake pedal is pressed. The shift lock solenoid works in conjunction with the brake light switch.

What Causes Code P0930?

A P0930 rarely has more than one cause, but others include:

• Faulty shift lock solenoid
• Faulty brake light switch
• Low battery voltage

What Are the Symptoms of Code P0930?

Simply put, your gear lever will not be able to shift out of park. Most modern automatic transmissions have a built-in override that is accessible via a screwdriver.
How Does a Mechanic Diagnose Code P0930?

First, your mechanic will bypass the shift solenoid through an access panel usually located near the gear lever itself. If this works, the solenoid will be tested for continuity and then replaced.

Common Mistakes When Diagnosing Code P0930

Although rare, low battery voltage can cause a shift solenoid to fail.

How Severe Is Code P0930?

Not being able to shift out of park essentially immobilizes a vehicle, so you can consider a P0930 as serious. However, it does not cause severe damage to a vehicle.

What Repairs Can Fix Code P0930?

• The most common repairs for a P0930 are as follows:
• Replacement of the shift lock solenoid
• Replacement of the brake pedal switch

Definition of Code P0931

Fault code P0931 detects a problem with the shift lock solenoid circuit.

What does code P0931 mean?

Code P0931 is a generic OBD-II fault code that indicates a voltage reading issue with the shift lock solenoid circuit. The shift lock solenoid is responsible for ensuring that the automatic transmission cannot shift out of the Park position unless the brake pedal is applied. When the system detects that the brake pedal has been pressed, the shift lock solenoid allows the gear lever to move from Park to Drive or Reverse. If the Powertrain Control Module (PCM) detects that the voltage reading from the shift lock solenoid circuit is abnormally high, code P0931 will be stored.

What causes code P0931?

Several different things can trigger fault code P0931:

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

What are the symptoms of code P0931?

Fault code P0931 will usually be accompanied by the Check Engine light illuminated on the vehicle’s dashboard. The gear lever will almost always be stuck in Park, so the car cannot be driven.

How does a mechanic diagnose code P0931?

Code P0931 will be diagnosed using a standard OBD-II fault code scanner. A qualified technician will observe the scanner’s freeze frame data to gather information about the code and see if other fault codes are present. If multiple different codes are detected, they must be addressed in the order they appear. The mechanic will then need to clear the fault codes and restart the vehicle to see if code P0931 is still detected. If not, it was triggered in error or represents an intermittent issue.

If the code persists after resetting, the mechanic will begin with a visual inspection of the electrical components in the system. Any loose or corroded connectors, or open or shorted wires will need to be replaced. The battery should then be checked to ensure it is properly charged.

Next, the shift lock solenoid must be inspected and tested for continuity. It is the most likely culprit for code P0931, but if the solenoid appears to be functioning, then the brake light switch will need to be checked.

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

Common mistakes when diagnosing code P0931

The most frequent mistake made when diagnosing code P0931 is failing to properly follow the OBD-II fault code diagnostic protocol. It is very important to follow the protocol, as it helps mechanics avoid incorrect repairs. For example, it is common to assume the solenoid is faulty, which risks overlooking damaged electrical components and replacing a functional part.

How severe is code P0931?

A car with fault code P0931 will likely not be drivable, as in most cases, the vehicle will not be able to shift out of Park. The vehicle will probably need to be inspected and repaired before it can be driven.

What repairs can fix code P0931?

Common fixes for fault code P0931 are:

•     Replacing the shift lock solenoid
•     Replacing wires and connectors
•     Replacing the brake light switch
•     Recharging or replacing the battery