Error Code P0750 is defined as Shift Solenoid ‘A’ Malfunction. This means there’s a malfunction going on in the transmission shift solenoid. This error code may also be seen with other shift solenoid error codes or transmission error codes.

This code is a generic trouble code, meaning it applies to all vehicles equipped with OBD-II system, or vehicles made since 1996 up to present. Specifications on the definition, troubleshooting and repairs of course, vary from one make and/or model to another.

Definition

The job of automatic transmission is to match the optimum power and torque characteristics of the engine to the driver’s desired acceleration and speed, through auto-selecting different gear ratios or speeds to bring power the wheels. Shift solenoid A allows the transmission to shift from 1st gear to 2nd gear by re-directing transmission fluid flow, which in the process, changes the position of the valve body’s shift valve.

Error Code P0750 is set when the PCM (powertrain control module, also referred as ECM or engine control module in other vehicle makes) detects a fault with the shift solenoid “A”. This means the PCM is not seeing the specified RPM change that happens during the shift from Gear 1 to Gear 2. The PCM controls the shift solenoid by commanding it when to engage or disengage. The fault will also put the vehicle into failsafe mode.

Common Symptoms

As with other error codes, P0750 activates the check engine light on the dashboard. Other common symptoms include:

  • Vehicle not shifting from 1st to 2nd gear or shifting rough shifting
  • Decrease in fuel efficiency

In other cases, vehicle may not show adverse symptoms of the conditions, while other vehicles may exhibit misfire-like symptoms.

Possible Causes

There are many factors that lead to Error Code P0750. Some of the most common ones include:

  • Defective shift solenoid A
  • Low level of transmission fluid
  • Contaminated or dirty transmission fluid
  • Fault at valve body assembly
  • Poor electrical connection for solenoid A

How to Check

As with many error codes, diagnosis for P0750 starts with the use of scan tool accessing the PCM to check for stored codes and freeze frame data associated with the codes.

Then, codes are cleared and the vehicle is taken for a test drive to verify the present codes.

If the code comes back, mechanics proceed on inspecting the vehicle’s transmission for any signs of damage, particularly leaks.

Next, they check the transmission fluid. If it’s at the within the level set by the manufacturer, then they will proceed on monitoring the shift solenoid A, both its performance and values.

If there are no conclusive faults found after the diagnosis steps above, there’s a good chance the transmission fluid needs to be drained and for the transmission pan to be removed to inspect the shift solenoid A, as well as the valve body itself.

How to Fix

Repairs for this error code are as easy as its diagnosis, which include:

  • Replacement of valve body
  • Replacement of shift solenoid A
  • Repairing or replacing faulty electrical connections
  • Changing transmission fluid
  • Correcting transmission fluid level based on manufacturer’s specifications

It is easy to misdiagnose Error Code P0750, especially if the diagnosis is done in the wrong order. The most common mistake is not paying attention to the manufacturer’s way of checking the transmission fluid. Some vehicles must be checked while the vehicle is running in neutral or in park.

Error Code P0750 can be a sign of a serious transmission problem. If transmission fluid is extremely dirty, or has particles clogging the valve body or shift solenoid, then the problem can be a case of mechanical wear inside the transmission.

For cases when the vehicle will not shift out of gear, the vehicle must not be driven, as this can cause serious safety concerns, which can also further harm the transmission. Thus, it is important to have this problem addressed as soon as possible.