What Codes Will This Page Cover?
- P0846 Transmission Fluid Pressure Sensor/Switch B Circuit Range/Performance
- P0847 Transmission Fluid Pressure Sensor/Switch B Circuit Low
- P0848 Transmission Fluid Pressure Sensor/Switch B Circuit High
Who Has the Lowest Price?
Some service centers will give you an online estimate to compare. Why drive around Town!?
What Is the P0846 Code?
Symptoms
Causes
Seriousness
Can I Still Drive?
Diagnose
Difficulty of Inspecting
Get Additional Help
The definition of code P0846 is “Transmission Fluid Pressure Sensor/Switch B Circuit Range/Performance.,” with code P0847 being “Transmission Fluid Pressure Sensor/Switch B Circuit Low” and code P0848 being “Transmission Fluid Pressure Sensor/Switch B Circuit High.” These codes mean that the powertrain control module (PCM) or transmission control module (TCM) has detected that the voltage coming from the transmission fluid pressure sensor (TFPS), specifically in switch “B,” doesn’t match its normal operating voltage according to factory specifications. You can see this generic powertrain code in almost any OBD-II-equipped vehicle with an automatic transmission.
You may also be interested in P0068 – Air Assisted Injector Control Circuit High
More About Error Code P0846
In automatic transmission vehicles, multiple solenoid groups direct your transmission fluid to different hydraulic circuits. That transmission fluid allows the transmission to change gears automatically. The transmission fluid pressure sensor, which can be a transmission fluid pressure switch in certain vehicles, reads the pressure in the transmission and sends it to the PCM or TCM, which allows the vehicle to determine the transmission operating pressure. If that reading isn’t accurate to what it expects, the engine might log the P0846 code.
What Are the Symptoms of a P0846 Code?
The P0846 engine code and other associated codes are usually due to an electrical failure, which means that your vehicle can often compensate for the issue in certain ways to avoid significant issues associated with it. The most common symptom is that the shift quality will just sort of “feel different,” with shift hesitation and potentially general drivability issues and performance issues, such as increased fuel consumption and difficulty accelerating, especially when going between gears. Certain engines that cannot compensate for this problem may also activate “Limp Mode,” also called “Limp Home Mode,” a failsafe mode where vehicle speed may be limited and certain features may not be available. You should also see the check engine light turn on in all these situations.
What Are Some Causes of a P0846 Code?
Usually, you’ll find that the P0846, P0847, and P0848 codes are just an electrical fault rather than due to mechanical issues. The problem commonly involves a faulty electronic pressure control solenoid or an issue with the transmission fluid pressure sensor. The wiring connecting to the sensor can also have a fault, leading to an issue with the electrical circuit and the voltage reading. You may also see this code occasionally due to low, contaminated, or dirty transmission fluid. The problem may very rarely lie with TCM or PCM failure, but this is uncommon and will almost always come with other codes.
How Serious Is the P0846 Code?
The P0846, P0847, and P0848 engine codes are quite severe. Your vehicle’s PCM or ECM must be able to monitor the pressure inside your vehicle’s transmission, as this helps your vehicle understand the proper shifting strategy and calculate the best gear to move into depending on engine load and vehicle speed. While this problem only has to do with one of your switches, meaning that your vehicle may still be able to read the hydraulic pressure levels, it’s still best to fix the problem to avoid transmission problems, like failed gear engagement, transmission overheating, and torque converter issues, all of which can be much more difficult and expensive repairs.
Can I Still Drive with a P0846 Code?
You will often physically be able to drive with the P0846, P0847, and P0848 codes active, but that doesn’t mean you should. The more you drive with these codes, the more likely you will experience more serious transmission problems, as your vehicle is more likely to have difficulty determining whether the hydraulic pressure is within ideal guidelines. If you get help from a professional mechanic earlier, you can save yourself from future problems where the code returns.
How Easy Is It to Diagnose a P0846 Code?
The diagnostic process for the P0846 diagnostic trouble code can be surprisingly difficult. Even though the problem usually lies with the electronics, you first need to check these electrical connections, then check other components within your vehicle’s transmission system, including transmission fluid level, transmission fluid leaks, and various connectors and wiring within this system. Because making common mistakes can lead to serious problems, as the transmission itself is often quite tricky to deal with, it’s often best for DIYers to leave this problem to an automotive diagnostician.
How Difficult Is It to Inspect a P0846 Code?
Inspecting the P0846 fault code can be even more difficult than code diagnosis. You’ll need your traditional code scanner and tools like a digital volt/ohmmeter and a reliable vehicle information source, like technical service bulletins, vehicle repair guides, and wiring diagrams. These can all help you determine what the main problem is and how you might be able to fix it, but it can be quite overwhelming to deal with them as a DIYer. A certified mechanic can help you inspect the problem and determine repair procedures that don’t require a follow-up repair.
Need Additional Help with Your P0846 Code?
Many people will need extra help with their P0846, P0847, and P0848 codes, so you should know how to find help.
To start, you should find an auto repair shop in your area. A local auto repair shop will provide you with the help you’re looking for while not being too inconvenient.
Additionally, sometimes your scan tool will turn up other codes alongside this one. The OBD-II database gives you information on all kinds of OBD-II system codes, so you can learn more about the problems you’re experiencing in your vehicle.
P0846 Q&A
Common Error Codes
Browse All OBD-II Codes
Get Recall Alerts
All recalls are considered serious. Stay safe. Take care of any recalls ASAP. The good news? Recall repairs are free when performed at a local dealer.