Definition of Code P0918

In vehicles equipped with automatic transmissions, a code P0918 means that the Powertrain Control Module (PCM) has recorded an intermittent fault in the gear shift mechanism range circuit, particularly regarding a specific lever position. The PCM uses data from the transmission range sensor to control engine speed, fuel dosage, ignition timing, and other driving factors.

What does code P0918 mean?

For most vehicles, a universal resistance level of 8 ohms is standard in this particular circuit. Any fluctuation greater than 10% (higher or lower) will result in a P2A00 code and a Malfunction Indicator Light (MIL). The heater circuit voltage must be consistent with the battery voltage, and any 10% variation can also lead to a stored fault code. Closed-loop O2 sensor readings that remain constant for 8 seconds or more can also result in a stored code and an illuminated MIL.

What causes code P0918?

In most cases, a code P0918 is due to a faulty transmission range sensor or an unadjusted transmission range sensor. The code is specifically for an intermittent problem, so in many instances, a code P0918 is caused by faulty, loose, damaged, or corroded wiring or contacts.

What are the symptoms of code P0918?

• Harsh shifting
• Failure to shift
• Limp-in mode
• Poor fuel economy

How does a mechanic diagnose code P0918?

A technician will need a good quality OBD-II scanner/code reader and a digital volt/ohmmeter (DVOM).

Most vehicles, especially Ford models, are designed with a variable resistance transmission range sensor. This switch is located on the transmission sensor shaft, where the lever slides along a row of contacts. When the gear lever is moved, this range sensor pivots and is moved to different contacts.

The contacts send different resistance levels to the PCM, depending on the gear lever position. The PCM reads these varying resistance and voltage levels as the selected gear ratio on the shift lever and acts on this information to determine shift points, engine ignition timing, fuel dosage, and other functions. The PCM also determines the appropriate transmission ratio based on engine load information and other factors.

Review all cables, connectors, and related components and repair/replace any open, shorted, corroded, or damaged wiring. Retest the system. If all cables, connectors, and components check out, connect the scanner to the diagnostic port and record all stored fault codes.
Check the transmission range sensor for battery voltage/ground signals.
If the ground or battery voltage circuits check as “open,” verify continuity/resistance in both circuits using the DVOM. Remember to disconnect all related control modules to prevent damage.
Using a factory diagram, test all associated circuits and the sensor itself for resistance/continuity. Compare with factory specifications and replace/repair any circuits, connectors, or components that do not meet specifications.
Clear the codes and retest the system.

Common mistakes when diagnosing code P0918

Often, technicians replace the entire transmission range sensor when adjustment would have been sufficient. In some cases, technicians have even been known to unnecessarily condemn the transmission.

How severe is code P0918?

A code P0918 can prevent a transmission from shifting and may put the vehicle in limp mode, meaning it will be barely drivable.

What repairs can fix code P0918?

Repair or replacement of:

Transmission range sensor
Corroded, loose, or faulty wiring

Definition of Code P0919

A fault code P0919 indicates that the vehicle’s Powertrain Control Module (PCM) has detected a discrepancy between the desired gear shift position and its reported position.

What does code P0919 mean?

The gear shift is the input that allows the user to control the vehicle’s engine power. In the case of a P0919 code, a PCM sensor has detected a malfunction in the gear shift’s ability to successfully handle the shift position.

What causes code P0919?

Faulty components in the transmission and corroded, broken, disconnected, or damaged wiring are the two most likely causes behind a P0919 fault code. Regarding faulty components, a misreading sensor can explain a P0919. This is especially likely if the practical symptoms of the code are mild or non-existent. In rarer cases, the PCM itself may be at fault. However, due to the high cost of replacing a PCM, it should only be considered after all other possible causes have been exhausted.

What are the symptoms of code P0919?

Although the severity of the error may differ from case to case, it is not uncommon for a P0919 gear shift error to result in the vehicle’s inability to shift gears. This will render the vehicle unusable.

How does a mechanic diagnose code P0919?

The P0919 code can first be identified by reading the code via an OBD-II scanner. From there, the sensors that initially recorded the fault should be checked for functionality. If the sensors themselves are working, carefully inspect the components related to the gear shift mechanism. All wiring and circuits related to the transmission should also be examined for any signs of corrosion, damage, or disconnection.

Common mistakes when diagnosing code P0919

Components related to the gear shift system may be mistakenly replaced if a faulty sensor is reporting a non-existent problem.

How severe is code P0919?

Since P0919 signals a clear error in the vehicle’s ability to properly control the gear shift position, it should be considered a very serious issue. In some cases, P0919 can render the vehicle unusable.

What repairs can fix code P0919?

• If the sensors are misreading a problem, they should be repaired or replaced based on the specifics of the issue.
• If there is nothing wrong with the sensors themselves, the components related to the gear shift mechanism must be checked, and any damaged or unresponsive parts should be repaired or replaced.
• All wiring should be inspected and repaired if necessary.
• After a set of repairs, the vehicle should be turned on and tested to see if the fault code recurs.
• In the rare cases where the PCM itself is faulty, it will need to be replaced. In this unlikely event, the associated control modules will also need to be reprogrammed.

P091A, P091B, P091C, P091D, P091E, P091F ISO/SAE Reserved

P028A, P028B, P028C, P028D, P028E, P028F ISO/SAE Reserved

P0920 – Forward Shift Actuator Circuit / Open

P0920 Possible Causes

• Faulty shift actuator
• Forward shift actuator wiring harness is open or short-circuited
• Poor electrical connection in the shift actuator circuit

What does it mean?

How to fix code P0920

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

P0920

Symptoms

Possible

Engine light on (or service engine soon warning light)

P0920 Meaning

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

Definition of Code P0921

When the Powertrain Control Module (PCM) detects an issue with the forward shift actuator circuit, a fault code P0921 is recorded. Other related fault codes include P0920, P0922, P0923, P0924, P0925, P0926, and P0927.

What Does Code P0921 Mean

The fault code P0921 is recorded when the PCM detects a variation in voltage from the forward shift actuator circuit that is outside the normal limits set by the vehicle manufacturer. Additionally, the Check Engine light illuminates with the storage of this code.

What Causes Code P0921?

Some potential causes of a P0921 fault code include a faulty forward shift actuator, shorted or defective wiring and connectors, a defective speed guide rail, and a faulty shift shaft. A mechanical failure within the transmission can also lead to the storage of this code. In rare cases, a faulty PCM or Transmission Control Module (TCM) may also cause this code.

What Are the Symptoms of Code P0921?

Some of the symptoms accompanying a P0921 fault code include difficulty or inability to shift into a forward gear. Another symptom of a P0921 fault code is reduced fuel consumption.

How Does a Mechanic Diagnose Code P0921?

Diagnosing a P0921 fault code by a mechanic is accomplished using an advanced scanner and a digital voltmeter. The mechanic must keep in mind to address fault codes in the order they were stored. The easiest way to do this is to download all freeze frame data and stored fault codes. When diagnosing a P0921 fault code, a mechanic should perform the following steps:

• Inspect the wiring, connectors, and components for damage.
• Clear the P0921 fault code and test the system to see if the code returns.
• If the code returns, use the digital voltmeter/ohmmeter to check the voltage and ground signal at the shift actuator switch.
• If no voltage or ground signal is detected, the mechanic must disconnect the PCM and all associated modules and test the continuity between the shift actuator switch and the battery ground.
• Additionally, the mechanic should inspect the shift shaft and forward guide rail for damage and ensure both are functioning properly.
• The mechanic should then clear the P0921 fault code again to see if it returns.
• If the fault code returns, the mechanic must then check the TCM for any faults using the digital voltmeter/ohmmeter to verify continuity.
• If the TCM checks out fine, the mechanic should then inspect and check the continuity of the PCM to see if it has malfunctioned.
• Finally, clear the P0921 fault code and test the system again to see if it returns.

Common Mistakes When Diagnosing Code P0921

A common mistake made by mechanics when diagnosing a P0921 fault code is not clearing the codes in the order they were stored. Additionally, mechanics may replace components that are not at fault instead of defective wiring or connectors, resulting in an inability to resolve the issue.

How Severe Is Code P0921?

Although a vehicle with a stored P0921 fault code on its PCM may still be drivable, continued use of the vehicle without fixing the code can lead to driving issues over time. It is best to correct the P0921 fault code to prevent the vehicle from failing to shift into a forward gear.

Definition of Code P0922

Fault code P0922 detects an electrical problem with the forward shift actuator circuit.

What Does Code P0922 Mean?

Code P0922 is a standard OBD-II fault code that indicates a problem with the forward shift actuator circuit. The forward shift actuator is a crucial component of an automatic transmission, responsible for engaging the shift into a forward gear. When the Powertrain Control Module (PCM) or Engine Control Module (ECM) detects an abnormally low voltage reading from the actuator circuit, fault code P0922 is then recorded.

What Causes Code P0922?

Potential causes of fault code P0922 include:

• Faulty forward shift actuator
• Shorted wires, corroded connectors, or other damaged electrical components
• Faulty forward guide rail
• Faulty shift shaft
• Mechanical malfunctions in the internal transmission
• In rare cases, a faulty PCM, ECM, or transmission control module

What Are the Symptoms of Code P0922?

Code P0922 will typically be accompanied by a Check Engine light illuminated on the instrument cluster. It is also possible for the car to have difficulty shifting gears or be unable to shift into a higher gear. If a forward gear is engaged, the car will likely be drivable, but fuel efficiency will probably be reduced.

How Does a Mechanic Diagnose Code P0922?

Code P0922 should be diagnosed using an OBD-II fault code scanner. A trusted mechanic will use the scanner to view freeze frame data and assess the code. The mechanic will also check for any other fault codes. If multiple codes are present, they should be addressed in the order they appear. The codes will then be reset and the vehicle restarted so the technician can see if the code remains detected. Otherwise, it is likely a case of an intermittent error, or perhaps a mistakenly detected code.

If code P0922 persists after resetting, the mechanic will visually inspect the electrical components, replacing any wires, connectors, or fuses that are damaged or otherwise compromised. The forward shift actuator will then be inspected, followed by the shift shaft and the forward guide rail. If the problem is still not resolved, the mechanic will need to perform a more in-depth inspection of the transmission, PCM, ECM, and transmission control module.

Whenever a component is replaced, the mechanic should pause the inspection, reset the fault codes, and restart the vehicle to see if the code persists. This allows the technician to know as soon as code P0922 has been resolved.

Common Mistakes When Diagnosing Code P0922

The most frequently made diagnostic error with code P0922 comes from not following the OBD-II fault code diagnostic protocol. It is very important that the protocol is followed step by step so that mechanics can perform diagnostics and repairs effectively and efficiently.

It is quite common to overlook simple electrical repairs in favor of more complex and incorrect repairs.

How Severe Is Code P0922?

Vehicles with a P0922 fault code will sometimes be drivable, but may not be, due to the inability to access a forward gear. However, continuing to drive a vehicle that has an active P0922 code can lead to serious transmission damage, so inspection and repair should be scheduled as soon as possible.

What Repairs Can Fix Code P0922?

Potential repairs for fault code P0922 include:

• Replacing the forward shift actuator
• Replacing the system’s electrical components
• Replacing or repairing the forward guide rail
• Replacing or repairing the shift shaft
• In rare cases, replacing the PCM, ECM, or transmission control module

Definition of Code P0923

Fault code P0923 indicates a problem with the forward gear shift actuator circuit.

What Does Code P0923 Mean

Code P0923 is a generic OBD-II trouble code that detects an issue with the forward gear shift actuator circuit of the transmission. The forward actuator is responsible for shifting the transmission into a forward drive gear (as opposed to reverse). If the Powertrain Control Module (PCM) or Engine Control Module (ECM) notices that the voltage reading from the forward gear shift actuator circuit is abnormal, code P0923 will be triggered.

What Causes Code P0923?

Several different issues can lead to the detection of fault code P0923:

• Faulty forward gear shift actuator
• Damaged or defective forward guide rail
• Damaged or defective shift shaft
• Mechanical problem within the internal transmission
• In very rare cases, a faulty PCM, ECM, or transmission control module
• Defective electrical components in the transmission system, such as shorted wires or open connectors

What Are the Symptoms of Code P0923?

When fault code P0923 is detected, the Check Engine light will likely illuminate on the vehicle’s dashboard. The car may also experience shifting issues and could be completely unable to engage a forward drive gear. If the car can be driven, fuel efficiency is likely to be reduced.

How Does a Mechanic Diagnose Code P0923?

Code P0923 will be diagnosed using a standard OBD-II fault code scanner. A qualified technician will use the scanner’s freeze frame data to gather information about the code and look for any additional fault codes that are present. If multiple codes are detected, the mechanic must address them in the order they appear on the scanner. Then, the fault codes will be reset, and the vehicle restarted so the mechanic can see if the code remains detected. If not, there was likely a false trigger or the code represented an intermittent error.

If the fault code returns, the mechanic will begin with a visual inspection of the electrical components in the transmission system. All wires, connectors, fuses, and circuits should be checked and replaced if damaged. The technician may then inspect the forward gear shift actuator, forward guide rail, and shift shaft.

If code P0923 is still detected, a more comprehensive inspection of the transmission and PCM will be necessary.

It is important for the mechanic to stop after replacing any component to reset the fault codes and restart the vehicle. This allows the mechanic to know when the issue has been resolved.

Common Mistakes When Diagnosing Code P0923

The most frequent mistake when diagnosing code P0923 comes from not following the basic OBD-II diagnostic protocol. This protocol must be followed at all times, step by step, to ensure that inspections and repairs are as quick, thorough, and efficient as possible. If the protocol is not followed, there is a risk of mistakenly replacing a complex component when a simpler fix was all that was needed.

How Severe Is Code P0923?

Fault code P0923 may or may not prevent a car from driving. Even if the car can be driven, operating it in this condition risks causing additional damage to the transmission. For this reason, code P0923 should be addressed as soon as it is detected.

What Repairs Can Fix Code P0923?

Possible repairs for code P0923 include:

• Replacing the forward gear shift actuator
• Replacing system wires, connectors, and circuits
• Replacing or adjusting the forward guide rail
• Replacing or adjusting the shift shaft
• In very rare cases, replacing the PCM, ECM, or transmission control module

The DTC P0924 is recorded when the computer detects an open circuit related to the gear shift reverse actuator. This is often caused by an electrical issue and should be resolved immediately.

How severe is the code?

If there is an electrical problem in the gear shift reverse actuator circuit, several transmission issues may occur, such as erratic shifting and the inability to engage or disengage reverse gear. Therefore, a diagnostic code P0924 is obviously quite serious.

Symptoms

Symptoms of a P0924 include:

• Erratic transmission behavior
• Difficulty shifting into or out of reverse gear

Causes

• Damaged wiring or connectors
• Faulty reverse actuator
• Damaged gear guide rail
• Damaged shift shaft
• Internal mechanical issues within the transmission
• ECU/TCM problems or failure

How to diagnose the code?

To determine what is causing an OBDII fault code P0924, your mechanic will need to check all electrical wiring, connectors, fuses, and relays in this circuit. The gear guide rail and shift shaft should also be inspected for signs of damage and misalignment. The gear shift reverse actuator itself will need troubleshooting to determine if it has failed. There could also be an internal mechanical failure to blame, or it might be an issue with the ECU or TCM.

What repairs will fix P0924?

• Repair or replace any damaged wiring or connectors
• Replace the gear shift reverse actuator
• Repair or replace the gear guide rail
• Repair or replace the shift shaft
• Fix internal mechanical defects
• Reprogram or replace the ECU/TCM

Related codes

P0920 – Forward shift actuator circuit/open
P0921 – Forward shift actuator circuit range/performance
P0922 – Forward shift actuator circuit low
P0923 – Forward shift actuator circuit high
P0925 – Gear shift reverse actuator circuit range/performance
P0926 – Gear shift reverse actuator circuit low
P0927 – Gear shift reverse actuator circuit high

Definition of Code P0925

The diagnostic trouble code P0925 detects a problem with the gear shift reverse actuator circuit.

What does code P0925 mean?

Code P0925 is a generic OBD-II trouble code that indicates an issue with the transmission reverse gear actuator circuit. The gear shift reverse actuator is responsible for shifting the transmission into reverse. When the Powertrain Control Module (PCM) or Engine Control Module (ECM) detects an abnormal voltage reading in the gear shift reverse actuator circuit, the P0925 trouble code will be triggered.

What causes code P0925?

Several different issues can lead to the P0925 trouble code being triggered:

• Faulty reverse gear actuator
• Mechanical problems in the transmission
• Defective reverse guide rail or shift shaft
• In rare cases, a faulty PCM, ECM, or transmission control module
• Damaged electrical components in the system, such as shorted wires or corroded connectors

What are the symptoms of code P0925?

The P0925 trouble code will likely be accompanied by the Check Engine light illuminated on the instrument cluster. The vehicle will also likely have trouble shifting into or out of reverse, or may refuse to do so entirely. Reduced fuel efficiency is also common.

How does a mechanic diagnose code P0925?

Code P0925 will be diagnosed using a standard OBD-II trouble code scanner. A reputable technician may use the scanner’s freeze frame data to assess the P0925 code and also look for any additional trouble codes that are present. If multiple codes are present, they should be addressed in the order they appear. The mechanic will then reset the trouble codes, restart the vehicle, and check if the code returns. If the P0925 code disappears, it was likely triggered incorrectly or represents an intermittent issue.

If the code returns, the mechanic should begin with a visual inspection of all electrical components in the system. Any damaged wires, connectors, fuses, or circuits will need to be replaced. Next, the mechanic will perform a thorough inspection of the gear shift reverse actuator, as well as the guide rail and shift shaft.

If the issue is still not resolved, a more in-depth inspection of the entire transmission system will be necessary.

Whenever a component is replaced during inspection and repairs, the mechanic should reset the trouble codes and restart the vehicle to see if the code returns. By doing this, the mechanic can know as soon as the problem is fixed.

Common mistakes when diagnosing code P0925

The most common mistake when diagnosing code P0925 comes from not following the OBD-II trouble code diagnostic protocol. Mechanics must adhere to the step-by-step protocol at all times to ensure their inspection and repair are as effective and efficient as possible. Failing to do so can result in addressing codes in the wrong order, missing a relatively simple fix, or not clearing the codes.

How severe is code P0925?

A vehicle with the P0925 trouble code can still be driven, although reverse gear may not be usable. If the car is driven with a detected P0925 code, severe transmission damage is at risk. For both of these reasons, the code should be addressed as soon as it is detected.

What repairs can fix code P0925?

Some repairs for code P0925 include:

• Replacing the gear shift reverse actuator
• Adjusting or replacing the reverse guide rail or shift shaft
• Replacing electrical components in the system
• Replacing the PCM, ECM, or transmission control module

When you shift your vehicle into reverse, a series of sensors informs the computer which gear you have selected. It then powers an electric motor to move the transmission into that gear. A DTC P0926 is logged when the ECU detects an abnormally low voltage signal on the gear shift reverse actuator circuit.

How severe is the code?

The diagnostic code P0926 is quite serious, as these transmission issues can actually prevent you from shifting into reverse or cause reverse to disengage.

Symptoms

Symptoms of a P0926 include:

> Transmission begins to operate erratically
> It becomes difficult to shift into reverse or to stay in reverse

Causes

• Damage to wiring and/or connectors
• Faulty reverse actuator
• Faulty gear guide rail
• Faulty shift shaft
• Internal mechanical issues
• ECU/TCM problems or failure

How to diagnose the code?

The first step in diagnosing an OBDII P0926 fault code is to check all cables, connectors, fuses, and relays on this circuit. The gear shift reverse actuator will also need to be tested. The gear guide rail and shift shaft should also be inspected for any signs of damage and misalignment. If no issues are detected so far, further diagnostics of the transmission itself, as well as the ECU and TCM, must be performed.

What repairs will fix P0926?

• Repair or replace any damaged wiring or connectors
• Replace the gear shift reverse actuator
• Repair or replace the gear guide rail
• Repair or replace the shift shaft
• Repair internal mechanical faults
• Reprogram or replace the ECU/TCM

Related Codes

P0920 – Gear Shift Forward Actuator Circuit/Open
P0921 – Gear Shift Forward Actuator Circuit Range/Performance
P0922 – Gear Shift Forward Actuator Circuit Low
P0923 – Gear Shift Forward Actuator Circuit High
P0924 – Gear Shift Reverse Control Circuit/Open
P0925 – Gear Shift Reverse Actuator Circuit Range/Performance
P0927 – Gear Shift Reverse Actuator Circuit High