P0787 Shift Timing Solenoid “A” Low Signal

P0787 – OBD-II Trouble Code Technical Description

On vehicles with an automatic transmission, DTC P0787 indicates a low signal from the shift timing solenoid valve “A”

What does the fault code mean P0787?

Trouble code P0787 indicates a low signal from the shift timing solenoid valve “A” in vehicles with an automatic transmission. These valves are responsible for controlling the movement of hydraulic fluid between different circuits, allowing gear changes to occur. In the case of P0787, there is likely a voltage problem with the shift timing solenoid valve “A”, which can cause the transmission to not operate properly.

Possible reasons

Some possible reasons for the P0787 trouble code:

• Malfunction of the solenoid valve “A” of gear shift synchronization: The valve may be damaged or malfunctioning due to wear, corrosion or other reasons.
• Electrical circuit problems: There may be opens, shorts, or other problems with the wiring or connectors that may cause insufficient voltage or signal interruptions.
• Transmission control module (TCM) problems: Malfunctions or malfunctions of the TCM can cause errors in the control of the shift solenoid valves.
• Low or dirty transmission fluid: Insufficient fluid level or contamination can reduce the efficiency of the solenoid valves and cause the P0787 code to appear.
• Mechanical problems with the gearbox: For example, wear or damage to the internal mechanisms of the transmission can cause the solenoid valves to not operate properly.
• Sensor Issues: Faulty sensors, such as transmission position sensors or pressure sensors, can cause the transmission to operate incorrectly.

These are just a few examples of possible causes of the P0787 code. To accurately determine the cause, it is recommended to diagnose the vehicle using specialized equipment.

What are the symptoms of trouble code P0787?

Some possible symptoms when trouble code P0787 appears:

• Gear shifting problems: The vehicle may experience difficulty or delay when shifting gears.
• Incorrect transmission behavior: The transmission may exhibit jerky or unusual behavior while driving.
• Increased fuel consumption: Improper transmission operation may result in increased fuel consumption due to inefficient gear shifting.
• Changing movement characteristics: The driver may notice changes in the vehicle's driving characteristics, such as higher engine speeds at certain speeds.
• Check Engine Light: When the P0787 code appears, it may cause the Check Engine light to come on on your vehicle's dashboard.

These symptoms may manifest differently depending on the specific problem and the make of the car.

How to diagnose a fault code P0787?

When diagnosing DTC P0787, follow these steps:

1. Checking the Check Engine indicator: First, you should check to see if the Check Engine light on your car's dashboard comes on. If so, this could be a sign of a transmission problem.
2. Using the Diagnostic Scanner: Using a diagnostic scanner, connect the vehicle to a computer to read the error codes. Verify that P0787 appears in the list of detected codes.
3. Checking Live Parameter Data: The scanner can also provide access to live parameter data such as speed sensor readings, transmission pressure and other transmission related values. Check these parameters for any anomalies.
4. Visual inspection: Inspect the electrical connections, wires and connectors associated with the shift timing solenoid valve “A”. Make sure all connections are intact and show no signs of damage or corrosion.
5. Checking the level and condition of the transmission fluid: Make sure the transmission fluid level and condition are within the manufacturer's recommendations. Low or contaminated fluid levels can cause transmission problems.
6. Solenoid valve diagnostics: Check the shift timing solenoid valve “A” for signal and proper electrical power. If necessary, replace or adjust the valve.
7. Additional tests: Depending on the specific circumstances, additional tests may be required, such as checking the speed sensors or transmission pressure sensors.

After completing these steps, you will be able to determine the cause and resolve the problem that caused the P0787 code. If you do not have experience in diagnosing automotive systems, it is recommended that you contact a qualified auto mechanic or service center.

Diagnostic errors

When diagnosing DTC P0787, the following errors may occur:

• Misinterpretation of data: The error may occur due to incorrect interpretation of the data received from the scanner. Inexperienced technicians may misread or evaluate data, which may lead to incorrect conclusions.
• Ignoring additional symptoms: Sometimes diagnosis may focus solely on the P0787 code, ignoring other symptoms or circumstances. This may result in missing important information about the problem.
• Incorrect cause identification: Diagnostics may lead to incorrect identification of the source of the problem. For example, you might conclude that the problem is the timing solenoid valve “A” when in fact the problem may be with the wiring or sensors.
• Incorrect repair recommendations: If misdiagnosed, the mechanic may make incorrect repair recommendations, which could result in unnecessary costs or incorrect repair of the problem.
• Skipping important diagnostic steps: Important diagnostic steps may be missed, such as checking electrical connections, transmission fluid conditions, or other components, which can slow down the process of determining the cause of the problem.

It is important to be diligent and diligent when diagnosing the P0787 code to avoid these errors and pinpoint the cause of the problem.

How serious is the fault code? P0787?

Trouble code P0787 indicates a problem with the shift solenoid valves, which are essential for the automatic transmission's transmission to function properly. This can have a serious impact on the performance and safety of your vehicle. If the problem is not corrected, it may result in improper transmission operation, harsh or unexpected gear shifts, which in turn can cause damage to other components and increase the risk of an accident. Therefore, it is recommended that you contact a qualified technician to diagnose and fix this problem as soon as possible.

What repair will help eliminate the code? P0787?

Resolving the P0787 code may require different actions depending on the cause of the problem, some possible actions are:

1. Replacing Shift Timing Solenoid Valve “A”: If the problem is with the valve itself, it should be replaced. This may require removing the transmission to access the valve.
2. Checking and replacing electrical connections: Check the electrical connections, wires and connectors associated with the shift timing valve “A”. If damage or corrosion is found, they should be replaced.
3. Diagnostics and replacement of sensors: Check the operation of transmission-related sensors such as the speed sensor or throttle position sensor. If necessary, they should be replaced.
4. Checking and servicing transmission fluid: Transmission fluid level and condition can affect transmission performance. Check the fluid level and condition, replace and service if necessary.
5. Firmware or software update: Sometimes the problem can be resolved by updating the software in the transmission control module.
6. Diagnostics and repair of other components: It is possible that the problem may be related to other components of the transmission control system, such as the engine control module or the power system.

If you are not experienced in performing this work, it is recommended that you contact a qualified auto mechanic or service center for professional diagnosis and repair.

What is P0787 Engine Code [Quick Guide]

P0787 – Brand-specific information

Deciphering the P0787 code for some popular car brands:

1. Chevrolet, GMC: P0787 – Shift Timing Solenoid A signal low.
2. Ford: P0787 – Shift/Timing Solenoid Malfunction
3. Toyota: P0787 – Shift Solenoid Circuit Low Voltage.
4. Honda, Acura: P0787 – Shift Timing Solenoid A signal low.
5. Nissan, Infiniti: P0787 – Shift Timing Solenoid A signal low.
6. BMW: P0787 – Shift solenoid “A” electrical fault.
7. Mercedes-Benz: P0787 – Shift Timing Solenoid A signal low.
8. Volkswagen, Audi: P0787 – Shift timing solenoid A signal low.
9. Hyundai, Kia: P0787 – Shift timing solenoid A signal low.
10. Subaru: P0787 – Shift Solenoid “A” Input Low.

These are common interpretations of the P0787 code for some makes of vehicles. It is also recommended to consult service documentation or contact a professional for accurate diagnosis and repair.