What Does the Engine Code P0842 Mean?

If your car is showing the P0842 engine code, you’ll need to get your transmission fluid pressure sensor checked out.
Written by Macy Fouse
Reviewed by Melanie Reiff
If your car is showing the P0842 engine code, your transmission fluid pressure sensor has recorded an issue with the transmission fluid or pressure. Be sure to get this looked at quickly as this engine code could also signify bigger issues.
Diagnostic trouble codes (DTCs) help pinpoint issues with your vehicle’s engine. When you get an engine code reading, it’s important to know the meaning of the code so you can find the source and tend to the issue. 
The #1-rated
car insurance
shopping and savings app
is here to walk you through the basics of DTCs and car insurance savings. Read on to learn more about the P0842 engine code: what it means, how to deal with it, and how much it costs to repair. 
Let Jerry find your price in only 45 seconds
No spam · No long forms · No fees
Find insurance savings

What does the engine code P0842 mean?

Definition: Transmission Fluid Pressure Sensor / Switch A Circuit Low
The P0842 engine code is a generic code signifying a problem with the transmission fluid pressure sensor/switch (TFPS). This part converts mechanical transmission to an electric signal for control modules. The TFPS is typically attached to the side of the valve within the transmission or screwed to the side of the transmission body.

How much will it cost to fix?

The time to diagnose should take about an hour of labor, which can cost anywhere between $75 and $150 per hour. Depending on the source of the issue, you could have to pay up to $400
In rare cases, you may need a new control module, which may cost up to $1,500.

What can cause the P0842 engine code?

When your car is throwing the P0842 engine code, it often means the TFPS got an unusually high voltage reading
The transmission fluid pressure sensor is intended to control the hydraulic pressure in the transmission and then transmits that data to the engine control module (ECM). It also notifies the computer if there’s any pressure loss.
Other issues that could trigger this engine code include: 
  • Contaminated or low
    transmission fluid
  • Jammed transmission fluid passages
  • Internal transmission failures
  • Faulty ECM
MORE: Does insurance cover engine failures? 

Common symptoms of the P0842 engine code

The signs accompanying this engine code can be obscure or random, other than the
check engine light
being illuminated. Other symptoms may include:
  • Slipping transmission
  • Car is hard to shift
  • Inability to shift
  • Overheating transmission
  • Decreased fuel economy
  • Disengagement from torque converter clutch
Most times the sensor, solenoid, or electric components need replacing. 

How serious is the P0842 engine code? 

Even if symptoms seem mild or unimportant, this code suggests a serious problem that should be dealt with as soon as possible. Your vehicle’s drivability will decrease until it’s undrivable. Leaving it unaddressed could also lead to more expensive repairs in the future.

Can I fix the P0842 engine code myself?

You may be able to repair the P0842 engine code yourself if you have mechanical experience. It’s crucial to correctly diagnose the problem before attempting any repairs, though. 
Depending on the cause of the issue, you may need to: 
  • Replace the pressure control solenoid
  • Refill, flush, or replace old transmission fluid
  • Clearing blocked transmission fluid passage
  • Fixing any mechanical internal transmission failures
  • Replacing the engine control module
It’s a good idea to start with the more common, smaller fixes before moving on to the major parts. And, of course, it’s always best to get a professional inspection to diagnose and repair the issue. 
MORE: How to know if a mechanic is taking too long with car repairs

Finding insurance for your vehicle

Car repairs can get pretty pricy, so make sure you aren’t overpaying for
car insurance
too. With
, it’s easy as pie. As a
licensed insurance broker
, Jerry can show you competitive quotes from 50+ top insurance companies in a couple of minutes. 
When you find the best coverage for you, Jerry takes care of it—no forms, no phone calls, no hassle. Just download the app, answer a few questions, and watch the magic happen.
“All of the insurance quotes I saw were over $600 a month because of my age. Then I stumbled upon
, and they sliced my price in half! They found me the lowest rate, thank goodness.” —Will V.
Jerry sends free alerts to keep your car up-to-date so you can avoid costly repairs
* checking your rate won’t affect your credit score
Get ahead of my car maintenance
* checking your rate won’t affect your credit score
Estimate your repair costs for free with GarageGuard™
Simplify your car maintenance with Jerry.
Try GarageGuard™

Easiest way to compare and buy car insurance

No long forms
No spam or unwanted phone calls
Quotes from top insurance companies
Find insurance savings