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P0841 OBD-II Trouble Code: Transmission Fluid Pressure Sensor/Switch A Circuit Range/Performance

check engine light

What the P0841 code means

The P0841 code indicates that the Powertrain Control Module (PCM) has discovered an abnormality in the transmission fluid pressure sensor circuit.

What causes the P0841 code?

There may be one or more causes for the P0841 code. One may be a faulty electronic pressure control solenoid. Another could be that there is something wrong with your transmission fluid pressure sensor, or that your vehicle has hydraulic blockages inside the internal transmission fluid passages. You may also have low transmission fluid, dirty or contaminated transmission fluid, mechanical internal transmission failures. A faulty PCM or transmission control module is rare but possible.

What are the symptoms of the P0841 code?

Unfortunately, there may be not be any noticeable symptoms. Or you may have a disabled shifting function or your torque converter clutch may fail to engage or disengage. Additional symptoms may include transmission slippage, harsh shifting, decreased fuel efficiency, an overheating transmission, and a stored code. Please be aware that other torque converter clutch, gear ratio, shift solenoid, lock up, or transmission slippage codes often fall under P0841.

How does a mechanic diagnose the P0841 code?

Always start any transmission diagnosis with an inspection of the transmission fluid dipstick. Be sure that the fluid level is within manufacturer’s specified recommendations and that the fluid appears to be in good condition. If the fluid smells burned or looks abnormal it is inadequate and should be changed. Burned fluid is a good indication that the transmission is operating at a low fluid level and unfortunately may mean that your vehicle has suffered major internal mechanical failure.

Also, be sure to look for burned or shorted wiring and always replace circuitry and connectors that appear to be in bad shape. If the system connectors, wiring, and components seem to be in good shape, connect your scanner to the diagnostic connector and record all freeze frame data and trouble codes. If the transmission fluid seems to be in good shape but the fluid level is low, add enough fluid to locate a leak and then repair it. If the transmission works properly and the code does not appear again, then it was probably caused by transmission slippage from a low fluid level and pressure condition. If the code returns and the transmission suffers from delayed engagement, you will need to check your pump pressure. To do this you will need a manual pressure gauge.

Common mistakes when diagnosing the P0841 code

It is often the case that electronic pressure control solenoid, transmission pressure sensor, and system wiring malfunctions are often overlooked and high-pressure pumps are often replaced when they do not need to be.

How serious is the P0841 code?

The P0841 code is serious and, unless you are highly skilled and possess the proper tools, should be looked at by a professional technician. If you do not attend to this problem quickly, it could reduce your gas mileage and could even affect your engine’s performance. It may also damage other components on your vehicle. It is always better to take your car to a technician as soon as you notice signs of change. Letting a problem go on for too long can have costly and at times irreversible effects on your vehicle.

What repairs can fix the P0841 code?

If your transmission fluid smells burned you will need to remove the transmission pan and check for clutch material and other debris. If you do find these contaminants in the transmission pan, you will need a total rebuild, a fluid flush and replacement, and a new torque converter. Otherwise your transmission will not function properly.

Additional comments for consideration regarding the P0841 code

Many older vehicles have sensor problems that occur due to prolonged stress on the drivetrain. Because a P0841 code can mean many things, it can be very difficult to diagnose and repair. Your best option may be to get your car into a technician who has the proper tools to diagnose your problem more accurately and efficiently.

Need help with a P0841 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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