P0848 OBD-II Trouble Code: Transmission Fluid Pressure Sensor/Switch B Circuit High

Our certified mechanics come to you · Get a fair and transparent estimate upfront

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0848 code

P0848 is a diagnostic trouble code (DTC) for "Transmission Fluid Pressure Sensor/Switch B Circuit High". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P0848 DIAGNOSTIC Get a fair and transparent estimate upfront

P0848 code definition

The storage of a P0848 trouble code means that the powertrain control module (PCM) has detected a problem with the transmission fluid sensor circuit. The pressure to the hydraulic pump is controlled by the PCM via the electronic pressure control solenoids. Some of the other trouble codes a mechanic might also see include P0845, P0846, P0847, and P0849.

What the P0848 code means

A P0848 trouble code signifies that there is a discrepancy in the pressure produced as opposed to what is actually needed by the transmission to function properly. The transmission needs the proper amount of pressure to shift properly and for the torque converter to engage and disengage like it should.

What causes the P0848 code?

Some common causes of a P0848 trouble code include a faulty transmission fluid pressure sensor, bad electronic pressure control solenoid, and blockage within the hydraulic lines of the transmission. Mechanical failure of the transmission can also lead to the storage of this code by the PCM. Mechanical failure can result from a low fluid condition or dirty and contaminated fluid within the transmission. A low fluid condition or dirty transmission fluid can also cause the PCM to store the trouble code. Though rare, another culprit could be the PCM itself.

What are the symptoms of the P0848 code?

In addition to showing no obvious symptoms of a problem at all, other than a lit Check Engine light, when storing a P0848 trouble code, the torque converter in the vehicle could fail to work properly, there could be problems with shifting, and the transmission could overheat. Other symptoms include a reduction in the fuel efficiency of the vehicle and the PCM placing the transmission into Limp-in mode.

How does a mechanic diagnose the P0848 code?

To properly diagnose a P0848 trouble code, a mechanic needs a code reader, digital volt/ohmmeter, manual pressure gauge, hydraulic pressure diagram, and the manufacturer's wiring diagram for the transmission fluid pressure sensor. The mechanic must also perform the following steps:

  • Start by checking the vehicle's transmission fluid, paying particular attention to fluid condition and smell.
  • If the fluid has a burnt smell or looks abnormal, remove the transmission pan and inspect it for the presence of debris, including parts of the clutch. If debris is found, rebuild the transmission before proceeding.
  • Also visually inspect the wiring, connectors, and any related components for damage.
  • Fix any detected leaks before filling the transmission with fluid. Also, clear the P0848 trouble code.
  • Next, the mechanic should start the vehicle and allow it to reach a normal operating temperature before test driving it to see if the code returns.
  • If the code returns, connect a manual pressure pump and using a hydraulic pressure diagram test the pressure produced by the hydraulic pump. The mechanic should then compare their findings to the manufacturer's specifications.
  • If, after clearing the code, it returns, use a wiring diagram from the manufacturer for the transmission fluid pressure sensor and a digital volt/ohmmeter to check the reference voltage and ground signal of the sensor.
  • If the sensor tests as open, disconnect any related control modules and test the circuits related to the transmission fluid pressure sensor for continuity and resistance.
  • The mechanic should also check the reference voltage and ground signal of the electronic pressure control solenoid and PCM with the volt/ohmmeter for fault.
  • Clear the P0848 trouble code and test the vehicle to see if it returns.

Common mistakes when diagnosing the P0848 code

A common mistake when diagnosing a P0848 trouble code is for the mechanic to overlook a faulty transmission fluid pressure sensor, electronic pressure control solenoid, or damaged wiring as the cause of the code and assuming it was stored in conjunction to a faulty high pressure pump when the pump is not the problem. Replacing the pump does not fix the problem and results in the trouble code returning.

How serious is the P0848 code?

Failure to repair a P0848 trouble code can result in no apparent problems with the vehicle to a complete failure of the transmission. Other problems vehicle owners can encounter when leaving a P0848 trouble code unfixed include problems shifting, slipping of the transmission, and the transmission becoming overheated.

What repairs can fix the P0848 code?

To repair a P0848 trouble code, the mechanic should perform the following:

Need help with a P0848 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.

trouble codes
OBD-II
P0848

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P0848 code.

SCHEDULE P0848 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

5,606

Rating Summary
5,180
205
50
34
137
5,180
205
50
34
137

James

40 years of experience
34 reviews
James
40 years of experience
Ford F-150 - Check Engine Light is on - Chagrin Falls, Ohio
Jim was great! Arrived on time, quickly diagnosed the problem and recommended further work. Very helpful, I’ll use Jim again and recommend to family and friends.

Roberto

11 years of experience
137 reviews
Roberto
11 years of experience
Nissan Titan - Check Engine Light is on - Spring, Texas
Roberto was very thorough with his explanation of repairs needed. I will contact your mechanic for future repairs.

Matthew

32 years of experience
839 reviews
Matthew
32 years of experience
Kia Optima - Check Engine Light is on - Yorktown, Virginia
Matthew Lerman was God Sent, and thank God for Your Mechanic,, you have my Vote Looking , Looking forward for more Business. Very Honest Guy

Robert

20 years of experience
38 reviews
Robert
20 years of experience
Honda Accord - Check Engine Light is on - Brentwood, California
He came earlier than on time and got the job done faster than I seen anyone else have . Solid honest hard working dude.


More related articles

P0125 OBD-II Trouble Code: Insufficient Coolant Temperature for Closed Loop Fuel Control
P0125 code definition Insufficient Coolant Temperature For Closed Loop Fuel Control What the P0125 code means P0125 is the OBD-II generic...
B1944 OBD-II Trouble Code: Airbag Crash Sensor #1 Ground Circuit Open
B1944 means there is a discrepancy in the airbag circuit in the poor ground on the #1 sensor, likely due to an open circuit in the crash sensor.
P0872 OBD-II Trouble Code: Transmission Fluid Pressure Sensor/Switch C Circuit Low
P0872 means the transmission fluid pressure is at a problematic level, likely due to a leak, defective pressure pump, or faulty transmission or PCM.

Related questions

My car has trouble code P0745, do I need to replace the solenoid?

Diagnostic Trouble Code P0745 refers to out of range voltage at a solenoid-operated valve that regulates hydraulic pressure in the transmission based on outputs from the Transmission Control Module (TCM). Code P0745 is set when the TCM sees an out...

My van won't start.. it's not the battery or the starter they are both brand new and I also had the starter relay changed ..

Hello and thank you for contacting YourMechanic. The code P1684 is for a battery disconnect from the battery to the computer system. The corrosion on the battery cable will block electrical current from traveling from the battery to the computer....

Stalling

Hi there: The EVAP system is comprised of multiple components. Although the gas cap removal is the easiest job to complete and the source of many of these problems, another common issue is caused by the EVAP vent solenoid. When...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com