The P0750 code is activated when the TCM (Transmission Control Module) detects a voltage drop when attempting to operate the transmission solenoid valve “A”.
If this code has been activated in your car, you are surely experiencing failures in gear changes, or the fail-safe mode has been activated. Although all this is to worry about, you must diagnose first to detect the cause of the failure and proceed to repair.
Let’s get started.
Transmission Solenoid Operation
Most automatic transmissions have at least 3 solenoids, which are identified by the letters A, B, and C. The P0750 code OBDII refers to a failure in solenoid A of your car’s automatic transmission.
The shift solenoid circuit allows the Powertrain Control Module (PCM) to monitor the shift solenoids to control the movement of fluid between the hydraulic circuits and also changes the gear ratio at the appropriate time.
In this way, the engine’s performance level is increased to the lowest RPM.
For the transmission to shift gears correctly, bands and clutches play an important role, therefore fluid pressure in the right place is necessary.
Transmission solenoids open or close valves in the valve body to allow transmission fluid to move to the clutches and bands. This way, the transmission shifts smoothly as the engine accelerates.
This process maximizes engine performance levels at the lowest possible rpm. Transmission solenoids are responsible for opening or closing the valves, allowing transmission fluid to flow to the clutches.
This diagnostic trouble code (DTC) is a generic transmission code. Error P0750 is considered a general code because it applies to all makes and models of vehicles.
What is the P0750 code?
Error code P0750 is defined as: “Shift solenoid A malfunction.” This means that there is a fault in one of the shift solenoids in your transmission.
This error code may also appear in conjunction with other transmission-related error codes. This is a generic fault code, meaning it applies to all vehicles equipped with the OBD-II system.
The automatic transmission’s job is to match the engine’s optimal power and torque characteristics to the driver’s desired acceleration and speed.
This is done by automatically selecting existing gears to propel your car. Shift solenoid A allows the transmission to shift from first to second gear by redirecting transmission fluid flow.
Error code P0750 It is set when the PCM (Powertrain Control Module) detects a fault in shift solenoid “A”. This means that the PCM is not seeing the specified RPM change that occurs during the shift from Gear 1 to Gear 2.
The PCM controls the shift solenoid by telling it when to activate or deactivate. The failure will also put the vehicle into fail-safe mode.
You may also be interested in Error Code P0760: Shift Solenoid C Malfunction
Symptoms of Code P0750
The symptoms of this failure are related to the operation of the transmission. The main sign that an error code P0750 is the malfunction indicator lamp (MIL), also known as the Check Engine.
Let’s see the list of common symptoms:
- The “Check Engine” control lamp on the control panel will light up. The code will be recorded in memory as a fault.
- Increases fuel consumption.
- The transmission can slip.
- The transmission does not shift gears, especially from first to second.
- Transmission overheating.
- Failsafe mode is activated.
In some cases, the vehicle may not show any adverse symptoms other than the activation of the Check Engine light, while other vehicles may show misfire-like symptoms.
Depending on the symptoms, the P0750 error can be moderate or severe. In case of problems with gear shifting, it is recommended to solve the problem as soon as possible.
Causes of Code P0750
Error code P0750 It may mean that one or more of the following problems have occurred:
- The transmission fluid level may be too low.
- Contaminating elements in the transmission fluid.
- The transmission filter may be clogged.
- The transmission fluid passages are clogged.
- Defective transmission pump or transmission valve housing.
- Shift solenoid valve A may be defective.
- Solenoid A cables or connectors in poor condition.
- Faulty shift solenoid A
- Valve body assembly failure.
- Other mechanical problems within the transmission.
All causes are related to the transmission and solenoid A, so fault detection can be done quickly and accurately.
How to Diagnose the P0750 Code
Let’s see the steps you must take to diagnose the code P0750.
- As a first step, you should consult the Technical Service Bulletins (TSB) corresponding to your vehicle model.
- Make sure there is a good level of transmission fluid. Also, check its condition as it could be contaminated.
- If you encounter problems with the transmission fluid, change the fluid and filter.
- As with many error codes, diagnosis of P0750 begins with the use of a scan tool that accesses the PCM to check the stored codes and review the freeze frame data associated with the codes.
- The codes are then cleared and the vehicle is taken for a test drive to see if the codes occur again.
- If the code returns, you should proceed to inspect the vehicle’s transmission for signs of damage, particularly leaks.
- Perform an inspection of all cables along with their respective connectors. If you notice worn cables or corroded connectors, you should make the necessary repairs or replace them.
- Next, proceed to monitor shift solenoid A, both its performance and its values. You must rely on a multimeter and the values offered by the manufacturer’s manual.
- If no conclusive faults are found after the diagnostic steps above, it is very likely that the transmission fluid will need to be drained and the transmission pan removed to inspect the A shift solenoid as well as the valve body.
This type of work must be carried out by a specialized service, since it involves disassembling the transmission and testing its components on a special bench. Solenoid A and valve body are checked and replaced if necessary.
How to Fix Code P0750
Repairs for this error code can be simple or complex, depending on the diagnostic results:
- Correction of the transmission fluid level according to the manufacturer’s specifications.
- Change of transmission fluid due to loss of properties or contamination. The filter must also be changed.
- Flush wash to clean the internal passages of the transmission.
- Replacing the valve body.
- Replacing shift solenoid A.
- Repair or replace faulty electrical connections.
- Repair or replacement of the faulty transmission pump, as well as the transmission valve housing.
Common Errors When Diagnosing Code P0750
It is easy to misdiagnose error code P0750especially if the diagnosis is made in the wrong order.
The most common mistake is not paying attention to how the manufacturer checks the transmission fluid. Some vehicles must be checked while the vehicle is running in neutral or parked.
Many times the failure is resolved only by topping up the transmission oil level. Therefore, it is necessary to carry out the diagnosis in the specified order to avoid changing parts unnecessarily.
Is Code P0750 Serious?
Error code P0750 It may be a sign of a serious transmission problem.
If the transmission fluid is extremely dirty or has particles clogging the valve body or shift solenoid, then the problem may be a case of mechanical wear within the transmission.
In cases where the vehicle does not shift gears, it should not be driven as this can cause serious safety issues, which can also further damage the transmission. Therefore, it is important to address this issue as soon as possible.
You may also be interested in Error Code P0706 OBD – Transmission Range A Range/Performance Sensor Circuit
We can say that the activation of this code greatly affects the driving of your car and your safety. We do not recommend that you drive in these conditions and have the vehicle diagnosed as soon as possible.
You can do part of the diagnosis yourself, such as checking the ATF level, checking the wiring or checking the voltage signals.
But if the case becomes complicated, the diagnosis and review must be done within the transmission, and you will need a specialized service.
If you want to know other articles similar to Code P0750. Shift Solenoid Malfunction “A” you can visit the category Fault Codes.