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

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P0848 DIAGNOSTIC 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 for $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 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$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
SCHEDULE P0848 DIAGNOSTIC Get a fair and transparent estimate upfront

diagnostic check engine light

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
P0848
OBD-II

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P0848 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.5/5

Number of Reviews

3,788

Rating Summary
3,460
163
43
24
98
3,460
163
43
24
98

Pardeep

18 years of experience
338 reviews
Pardeep
18 years of experience
He was great - friendly, fast and knowledgeable.
2012 HYUNDAI SONATA - CHECK ENGINE LIGHT IS ON - SAN JOSE, CALIFORNIA

Joe

40 years of experience
576 reviews
Joe
40 years of experience
Joe was early for his appointment and was in his usual positive mindset. Joe went right to work to determine the problem and came up with solutions to repair my car. Joe is very professional and an asset to your company (My Mechanic) and to me. Thanks.
2004 JAGUAR S-TYPE - CHECK ENGINE LIGHT IS ON - PORT RICHEY, FLORIDA

Matthew

30 years of experience
372 reviews
Matthew
30 years of experience
Mr. Matt is awesome!
1999 NISSAN MAXIMA - CHECK ENGINE LIGHT IS ON - NORFOLK, VIRGINIA

Jonathan

19 years of experience
304 reviews
Jonathan
19 years of experience
I have used Jon several times now and won't use anyone else. I highly recommend him [so long as he doesn't get so busy he isn't available when I need hem ;-) ].
2005 CHRYSLER PT CRUISER - CHECK ENGINE LIGHT IS ON - WESTMINSTER, COLORADO

More related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...

Related questions

Q: Q: Code p0421

Are there other codes set? This code, by itself, P0421 indicates that the engine management system detected the catalytic converter is performing below expected standards. This means the engine is sending contaminants (unburned fuel, oil fumes, etc.) down the exhaust,...

Q: OBD support

Hey there. If you have the OBD-2 connector under the dash directly under the steering column, then the ELM327 will work to scan the vehicle after you download the app. I can tell you that this adapter is very cheaply...

Q: Trouble starting car when cold

The starting issues scream timing. The typical causes that set these codes are the cam and crank position sensors. The only option you have not tried to my knowledge is the camshaft position sensor. I would start there. With all...

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.

1-800-701-6230 · hi@yourmechanic.com