P0871 is a somewhat rare diagnostic trouble code. While your Nissan Sentra’s check engine light will come on, this particular code indicates that there’s something wrong with the transmission, specifically the transmission fluid pressure sensor switch “C”. Show
It’s a generic code, so P0871 has the same definition for any vehicle made for the 1996 model year and up. Before doing anything, check your Sentra’s transmission fluid. Make sure that it is full and doesn’t look burnt or otherwise discolored. Abbreviations used in this article:
Here’s the definition of P0871 for the Nissan Sentra broken down by its individual parts. Transmission Fluid Pressure Sensor/SwitchThe TFPS has two primary jobs:
Circuit “C” Range/PerformanceThe TFPS converts the hydraulic pressure data into a voltage signal that your Sentra’s TCM/PCM can use to control the transmission. P0871 occurs when this signal is out of the normal operating range for this signal. So you have two scenarios:
P0871 Symptoms: Nissan SentraHere are the most common symptoms associated with P0871 in the Nissan Sentra:
We don’t recommend driving with this code, as it can be an early warning of transmission failure. Nissan Sentra P0871 Causes + DiagnosisDiagnosing P0871 in the Nissan Sentra can be challenging, due to the location of the TFPS sensor and the wiring associated with it. 1. Check for Other Codes and TSB’sThe first thing you want to do is check for other diagnostic codes. They can provide valuable clues to what’s going on inside your transmission. TSB’s are technical service bulletins. Nissan uses them out to deal with common and well-known vehicular issues. Check to see if there are any related to your problem. You can get them from the NHTSA website. It is possible that this code was thrown with the very similar P0841. 2. Check the Transmission FluidIf your Sentra’s transmission fluid is too low or too high, it can throw this code. It only takes a second to look. Make sure you check it on a level surface to get a good reading. 2. Inspect the TFPS WiringThe next thing you’re going to want to do is to inspect the wiring going to your Sentra’s TFPS. If it’s burnt or damaged, you’ll need to replace/repair it. After that, clear your Sentra’s trouble codes and see if P0871 comes back. Whether or not you’re going to be able to access the TFPS is going to determine whether most people can continue diagnosing P0871. Sometimes the TFPS can be accessed from the outside of the transmission. You may need to open the transmission, which means sending it to a transmission repair shop. Wiring issues are the most common cause of P0871. Take your time and make sure that the harness is in good shape. 3. Other Causes
While a bad TFPS sensor is highly likely, make sure that the voltage going to it is correct and doesn’t change when wiggling the harness before replacing it. ConclusionDiagnosing P0871 is relatively straightforward. The real issue is getting to the wiring and TFPS. Good luck fixing your Nissan Sentra! What is transmission fluid pressure sensor?The transmission fluid pressure sensor (TFPS) is responsible for converting transmission pressure into electrical signals for the powertrain control module (PCM) or transmission control module (TCM).
How do you check transmission fluid pressure switch?In order to test the switch you can connect your multimeter between the pin and the senders body. You should find the switch is closed while the engine is at rest. When the engine is running, the switch should open. As you can see this switch has only one pin, so the switch works between ground and the pin.
How do I fix code P0843?What repairs can fix the P0843 code?. The most common repairs for a P0843 are as follows:. Replacing the transmission fluid pressure sensor.. Replacing the transmission fluid pressure control solenoid.. Replacing and flushing the transmission fluid.. Repairing damaged or blocked fluid hoses.. |