Transmission fluid pressure sensor switch a circuit range performance

Every automatic transmission runs with a fluid called automatic transmission fluid [ATF] or transmission oil. The job of the ATF is to lubricate the reciprocating components inside the transmission unit. This prevents speeding up component wear, transmission overheating and thus enables smooth gear shifting.

The transmission oil pressure switch/sensor is an essential drivetrain component. It monitors and regulates the amount of pressure build-up in the transmission crankcase as the fluid circulates. It then signals the PCM about the fluid pressure. The PCM adjusts how the transmission behaves based on the signal it receives. This allows for smooth and optimal gear changes between different gear ranges.

Many newer vehicles have more than one transmission oil pressure switch. The location and sizes vary depending on car make and models. When this switch fails, the car computer will register some trouble codes like P0840 , P0841, and check engine light.

This article will discuss the meaning of error code P0841, causes, symptoms, diagnosis mistakes, how to diagnose, and fix. Sit back and have a 5 minutes read.

Code P0841 Definition

Transmission Fluid Pressure Sensor/Switch “A” Circuit Range Performance

What Does P0841 Mean?

Diagnostic trouble code [DTC] P0841 means transmission fluid pressure sensor switch “A” circuit range performance. P0841 code means the Powertrain control module [PCM] or Transmission control module [TCM] has discovered out of range or abnormalities in the transmission fluid pressure sensor circuit. It is a generic powertrain error code registered on vehicles manufactured from 1996 and upwards.

The transmission fluid pressure switch [TFPS] converts transmission pressure into an electrical signal for the powertrain control module to understand. The car computer uses this electrical signal to determine the transmission’s operating pressure. If the transmission fluid “A” differs from the stored data on the powertrain control module, the car computer will register the P0841 fault code.

This code is an electrical problem, mechanical problems with a stuck valve, issues on the valve body, and low operating pressure.

What Are the Symptoms of Code P0841?

P0841 has little to no noticeable symptoms. The common signs are shifting functions, torque converter’s inability to engage and disengage the clutch. Other symptoms include;

• Transmission overheating
• Bad gas mileage
• Check engine light illumination
• Transmission slippage
• Hard gear shifting
• Transmission solenoid issues

What Cause of Code P0841?

Several factors can cause the car computer to register error code P0841 aside from the transmission fluid pressure switch. The PCM can write this code because of issues with other drivetrain components. If you have inaccurate readings, ensure you check all system components. Here are potential causes of P0841 on dodge and other vehicles;

• Short voltage in the signal circuit to the transmission fluid pressure switch
• Open in the signal circuit
• Low transmission fluid
• Dirty transmission fluid
• Mechanical internal transmission failures
• Defective TFPS sensor
• Hydraulic blockage in the internal fluid passage
• Faulty TCM or PCM [rare but possible].

How Serious Is Code P0841?

P0841 Jeep or any vehicle is pretty severe. Unless you’re a gearhead with proper tools, it’ll require the services of a professional mechanic to track and fix the cause. If you cannot fix this problem on time, it will cause several drivability issues such as harsh gear shifting, transmission overheating, transmission slipping, and bad gas mileage.

P0841 will affect the overall engine performance. It can also damage other drivetrain system components. Hence, I advise you to visit a mechanic garage whenever you notice any drivability issues. Driving with a defective component for a long time will drop expensive repair bills on the table. It can cause catastrophic damages and may leave you stranded in the middle of nowhere.

Code P0841 Common Diagnosis Mistakes

The common diagnosis mistake amongst mechanics is overlooking transmission pressure sensors, electronic pressure control solenoids, system wiring harnesses, and connectors. Instead, they often replace high-pressure pumps before looking at the common and minor issues.

Tools Needed to Diagnose Code P0841

P0841 requires the following tools for proper diagnoses;

• OBDII scan tool
• Digital multimeter

How to Diagnose Code P0841

Always start with the transmission fluid dipstick when working on error code P0841 Chrysler. Ensure the fluid is not dirty and within the automaker’s specified mark. If the fluid is dirty or smells burnt, flush and replace it with new fluid.

If the fluid is below the manufacturer’s specified mark, top it with extra oil. Burnt fluid is an excellent sign of transmission overheating and or low transmission fluid. It can also mean the transmission has suffered from internal mechanical failures.

The next thing to check is the wiring harnesses. Ensure the wiring harness and connectors are in good shape. Replace any burnt circuits and connectors.

If, after visual inspection, it seems the wiring harness, connectors, and circuitry are in good working conditions, read the vehicle freeze frame data with an OBD2 scan tool.

If you observe a low fluid level, top the fluid and check for leaks and repair it. If you fix the problem and the error code disappears after repairing and refilling the fluid, the vehicle may have had transmission slippage.

Low fluid pressure and level is the cause of transmission slippage. If the code returns and is accompanied by a delayed engagement issue, the transmission pump is likely failing. Check the pump pressure with a manual pressure gauge. So, how do I fix code P0841?

How do you fix P0841?

There’s a lot to consider when troubleshooting and repairing P0841 fault codes. Always avoid following generic repair guides. Remember to follow diagnosis instructions and repair procedures for your specific vehicle.

Every vehicle repair manual has all repair guides to tackle any problem. You can also use your manufacturer’s service bulletin to diagnose all diagnostics trouble codes. You can also subscribe to your car’s ALLDATA subscription.

Remember, generic repair guides may not work for your specific car model. What may fix P0841 Nissan Altima may not fix P0841 Mazda 3. You can consider contacting your mechanic to diagnose and rectify the issue.

Last words

Many older vehicles suffer drivability issues because of prolonged use. It can be very difficult to diagnose and fix error code P0841 because several factors can trigger it. 

If your vehicle’s onboard computer registers this code, and you notice the signs above, your best option may be to contact a certified mechanic. A gearhead with proper tools will diagnose the issues more accurately and effectively.