P0845 OBD-II Trouble Code: Transmission Fluid Pressure Sensor/Switch B Circuit

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

SCHEDULE P0845 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0845 code

P0845 is a diagnostic trouble code (DTC) for "Transmission Fluid Pressure Sensor/Switch B Circuit". 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 P0845 DIAGNOSTIC Get a fair and transparent estimate upfront

Check Engine Light

P0845 code definition

The P0845 code is detected with an abnormal voltage reading from the transmission fluid pressure sensor circuit alerts the PCM. This code is often stored with other torque converter clutch, shift solenoid, transmission slippage, gear ratio, or lock up codes.

What the P0845 code means

In order to determine the right amount of pressure for transmission operation, several sensors and readings are utilized by the PCM. If the right amount of fluid pressure is not detected from the fluid pressure sensor, it means that the right amount of transmission pressure cannot be achieved. This detection will cause the PCM to store the P0845 code.

What causes the P0845 code?

Typically, the P0845 code is caused by a faulty electronic pressure control solenoid. However, a faulty transmission fluid sensor may also be to blame. Other causes include:

  • Blocked transmission fluid passages
  • Internal transmission failures
  • Low transmission fluid
  • Contaminated or dirty transmission fluid
  • A faulty PCM or TCM, in very rare cases

What are the symptoms of the P0845 code?

Before the P0845 code is detected, the vehicle’s owner may notice harsh shifting, a slipping transmission, an overheated transmission, decreased fuel efficiency, or a complete failure to engage or disengage from the torque converter clutch. The Check Engine light should also be illuminated.

How does a mechanic diagnose the P0845 code?

In order to diagnose the P0845 code, the mechanic should begin by verifying the code with an OBD-II scanner. Any issues with transmission components should always be addressed first with an inspection of the transmission fluid. If the fluid is low, it should be filled; if it is dirty or smells burnt, the system may need to be flushed and be refilled with clean transmission fluid.

After this step, the mechanic should clear the code and retest the system. If the code reappears, they will need to continue on with other diagnostic procedures, beginning with a check of all electrical components. After each potential repair is attempted, the code should be cleared and the system should be rechecked, to ensure that the right fix is narrowed down.

Common mistakes when diagnosing the P0845 code

It is common for the high pressure pump to be replaced, when in fact the transmission pressure sensor itself, or the electronic pressure control solenoid or other wiring malfunctions were to blame. It’s important that all electrical components be checked before replacing any major parts, as shorted connections are frequently the issue.

How serious is the P0845 code?

The P0845 code is considered very serious, and its presence indicates an issue that should be addressed right away. If this issue is not resolved as soon as the code is detected, it could lead to a vehicle that is not operational, or that is unsafe.

What repairs can fix the P0845 code?

There are many ways that a technician can address a P0845 code detection. They include:

  • Replace a faulty electronic pressure control solenoid.
  • Replace a faulty transmission fluid sensor
  • Cleaning blocked transmission fluid passages.
  • Addressing any internal transmission failures.
  • Refilling low transmission fluid.
  • Flushing the system of contaminated or dirty transmission fluid, and replacing it with clean fluid.
  • Replacing a faulty PCM or TCM, in very rare cases.

Need help with a P0845 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
Check Engine Light
P0845

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

SCHEDULE P0845 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

Honorio

16 years of experience
658 reviews
Honorio
16 years of experience
Quick, courteous and called ahead of time. Great he came out on a Sunday.
2005 HONDA ODYSSEY - CHECK ENGINE LIGHT IS ON - PALO ALTO, CALIFORNIA

Joseph

24 years of experience
351 reviews
Joseph
24 years of experience
Joseph was awesome! On time, professional, efficient and very knowledgeable. I will definitely be calling him again. No comparison to dealing with a shop or dealership. I would add a star if I could!! :)
2003 TOYOTA LAND CRUISER - CHECK ENGINE LIGHT IS ON - SUGAR LAND, TEXAS

John

37 years of experience
48 reviews
John
37 years of experience
John was great, a very nice and respectful person, as well as a thorough mechanic. He explained anything I asked about and didn't talk down to me as if I couldn't understand it.
2014 DODGE GRAND CARAVAN - CHECK ENGINE LIGHT IS ON - ANTIOCH, CALIFORNIA

Brett

22 years of experience
121 reviews
Brett
22 years of experience
Very helpful and informative know exactly what was wrong I just recommended him to my sister
2009 HONDA CIVIC - CHECK ENGINE LIGHT IS ON - CHARLOTTE, NORTH CAROLINA

More related articles

P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP)...
P0359 OBD-II Trouble Code: Ignition Coil I Primary/Secondary Circuit Malfunction
P0359 code definition The P0359 code indicates that a fault has been detected in one of the vehicle’s ignition coils, generally the number 9 coil. This code can also be associated...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.

Related questions

Q: Q: Timing chain problem?

It could very well be a timing chain problem. The P0016 and 17 indicate that the camshaft sensors are sensing the camshaft in a position that does not logically correspond with the crankshaft. The P0302 and P0355 codes are misfire...

Q: P101 keeps coming on Yukon 2003 after replacing with a new one, cat converters were installed fixing the p420 problem,

Claimed by Jay Safford

Q: Car cranking problem being a bad fuse box?

Fuse boxes can and do go bad every once in a while. While it is rather rare, it is not unheard of. If there has been any sort of damage in the area, these are more likely to fail. The...

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