On most modern cars, trucks, and SUVs, the transmission and components inside are monitored by a series of sensors and switches that relay information to the ECM every millisecond.
One of these components is the transmission oil pressure switch, which is designed to monitor the amount of pressure built up inside the transmission case as fluid flows through a series of chambers and channels to permit the transmission to smoothly shift gears. Like any other sensor, it can become damaged or simply wear out over time. The transmission oil pressure switch is attached to the transmission case and was engineered to monitor and relay the oil pressure inside the transmission to the on board computer found in most vehicles.
Older vehicles without ECM also utilize a transmission oil pressure switch, but instead of sending data to a computer, the information is displayed on a gauge found on the dashboard, or is sent to a monitoring console that illuminates a light on the dash if a problem is detected.
Most of today's vehicles have multiple sensors that review aspects of the transmission from oil pressure to heat, RPM, and even some that control the cruise control on your vehicle. The transmission oil pressure switch is unique in that its sole purpose is to collect data about the pressure found inside the transmission case, which impacts the timing and operation of shifting a vehicle to a higher or lower gear if needed.
Due to the fact that it's located underneath the vehicle, the transmission oil pressure switch is subject to extreme conditions and working in a harsh environment.
It can wear out, break, or fail — which may lead to it not working at all or worse, relaying incorrect data to the vehicle's ECM which can cause the transmission to work incorrectly, potentially damaging components in the process. If this component wears out or breaks, it will trigger a series of warning signs to occur, which may alert the driver that a problem with this part exists and that it needs to be replaced as soon as possible.
Noted below are a few of the indicators that the transmission oil pressure switch is damaged and needs to be replaced by a local ASE certified mechanic. The transmission oil pressure sensor's primary function is to relay information to the ECM that regulates control of the transmission. However, if the switch is damaged or not sending information correctly to the ECM, the transmission may default into "limp" mode. In this case, the transmission will be locked into the "limp" gear, such as a third or fourth higher gear ratio, which allows the vehicle to run at a lower RPM as the driver brings the vehicle to a mechanic or back to their home.
This will lock up until the error codes are downloaded from the ECM by a professional mechanic and the issue that triggered the "limp" mode is resolved. If you're driving down the road and your transmission sticks in a higher gear, drive home and contact a professional mechanic to inspect the issue.
Odds are that the transmission is in this default gear due to a malfunction of some sorts that must be repaired before you drive again. One of the most common symptoms of a damaged oil pressure switch is a loose fitting wire that is attached to the switch and relays the information to the ECM. When the wire is not secured, it can cause the sensor to register lower pressure than what is inside the transmission.
This faulty information will be noticed by the computer which can cause shifting difficulties especially downshifting.
Just like the above situation where the transmission has difficulty shifting due to a faulty oil pressure switch, this same problem can cause the transmission to not shift when it should. In this situation the engine RPM will be much higher than it should when it triggers the transmission to shift into a higher gear. The oil pressure switch of the transmission is vital for the smooth and efficient operation of the vehicle.
If you recognize any of the above warning signs or symptoms, contact a professional ASE certified mechanic in your area to have them replace the transmission oil pressure switch as soon as possible if this indeed is what is causing your problems. The most popular service booked by readers of this article is Vehicle Drivetrain Inspection.
Our certified mobile mechanics make house calls in over 2, U. Fast, free online quotes for your car repair. Schedule Vehicle Drivetrain Inspection.So how do you find out what problems are occurring? Any duplicates or errors? It's not us. Don't waste your time wasting ours! If you are interested in advertising a for-profit service, contact us. Find something helpful? Spread the word.
Share on Facebook Retweet this page Email this page. Add Complaint. The contact owns a Jeep Liberty ltd edition. The contact stated that the driver was on a dirt road driving approximately 15 mph when she crossed over a creek. The vehicle came to a complete stop; however, the engine was still on.
There were 3 people in the vehicle and one of the passengers in the back seat noticed that sparks were coming from underneath the vehicle. The vehicle caught fire and was destroyed. The failure and current mileages were 78, The contact owns a Jeep Liberty.
While driving 50 mph, the vehicle would not shift into third gear. The dealer stated that the plate sheared the bolts off the transmission, which caused the metal to enter the transmission. The dealer stated that the transmission needed to be rebuilt. As of August 31,the vehicle has not been repaired.
The VIN and engine size were unknown. The current and failure mileages were 89, Search CarComplaints. The contact complained about the effect that the ball joint had on the tires. The contact stated that no matter what speed she was driving at, but usually at about 15 mph she felt and heard the suspension in the car shifting whenever she hit a bump.I have a check engine light on and the computor says it is the speed sensor. I have replaced the sensor and yet the check eng. What else could this be?
Unlike many of the other Jeeps, where the speed sensor is located in the tail housing of the transfer case, the vehicle speed sensor for your Liberty is located inside the rear differential.
Transmission input and output speed sensors will not cause a problem of this type. The sensor picks up on the signal induced by the tone ring attached to the carrier and ring gear assembly. The sensor reads all the little teeth that wiz by; looking for the one spot that has a big gap.
P0841 JEEP - LR Pressure Switch Rationality Fault
Based on the frequency that the sensor finds the gap, the computer can make a few quick calculations and find out how fast the vehicle is moving. This system is totally independent of the wheel speed sensors found at each wheel for the vehicles ABS system. If you have replaced other sensors, you haven found the right one, the sensor in the rear differential is the one that causes this problem. More often than not, the wires for the sensor become chaffed, bent, kinked, or broken.
When that happens, the computer loses contact with the sensor. The bracket on the housing that holds these wires often rubs through them causing a short. The contact point for the bracket is inches up the wire from the sensor.
Very carefully inspect the wires in that area. You should be able to see the damaged wire s. Replace any section of wire that even comes close to suspicious. Be sure to cut out and replace 2 inches of wire 4 inches total on both sides of the damage. The reasoning is that water can enter the wire at the point of damage, and corrode the wire.
Be sure to cut out enough wire to get down to the healthy stuff. Then, solder in the new wire and be sure to use shrink wrap and use some electrical tape to seal up your work. The other common issue is caused by dirty diff fluid. When the rear differential lube is very dirty it will screw with the reading that the sensor is supposed to take.
In order to fix this you must do a differential service. Do a good job of letting the differential drain, a clean those gears and tone ring until they are clean enough to eat off of, use 3 cans of brake clean if you have to, but get it all CLEAN. Problem solved.Login Register. Remember Me? Forum General Discussions Transmission sensor fix for Jeep grand cherokee. View Poll Results: Was this write-up helpful?
Voters 2. You may not vote on this poll. Results 1 to 1 of 1. Thread: Transmission sensor fix for Jeep grand cherokee. The next morning when she went to pull out of our driveway she thought the transmission felt like it was slipping.
That night when she returned from work I took it for a test drive.Here's Why Changing Your Transmission Fluid Can Cause Damage
I backed out the driveway in reverse with no problems. I stopped and held the brake and pushed down on the accelerator a little holding it in a set place to check for a slipping condition. I tried to drive forward and again it took off real slow like the brakes were stuck partially on even though I was pushing the accelerator down quite a bit.
I then knew that the transmission was starting off in third gear instead of first gear. Begin by removing the bolts from the front of the transmission oil pan. Then start removing the bolts on the sides of the pan working your way to the back. With the drain pan under the transmission begin loosening the bolts on the rear of the oil pan. I use denatured alcohol or electrical parts cleaner to clean the pan because it leaves no residue. Unplug the wire from the Governor Solenoid and from the Governor sensor by prying lightly on the little plastic clip on the top of the connector while pulling out.
Remove the bolts and screws. The solenoid and holding plate will fall in your hands. Place clean transmission oil on the New pressure sensors rubber ring and insert it into the hole it came from.
Lastly, place the holding cover over the solenoid and sensor so it holds them in place it locks around the pressure sensor.Worried about potential repair costs? An extended warranty can provide peace of mind. See our lemon odds and nada odds page to see vehicles with no repairs or vehicles with more than three repairs. To see how frequently Jeep Liberty problems occur, check out our car reliability stats.
All years. Jeep Liberty repairs by problem area. Jeep Liberty engine repair cost distribution. See most expensive repairs Worried about potential repair costs? Chart based on repair trips. The repair cost chart excludes repairs made under warranty, do-it-yourself repairs, and repair trips that include maintenance. Jeep Liberty Engine not specified. Took it in to dealership for warranty work.
Took a few days since a new fuel rail had to be shipped from Europe. No fix. Fuel pressure sensor replaced, SES lamp cleared. On way home, diesel engine stumbled at idle and acceleration again. Found wire loom going to engine from PCM cut open with a raz. Engine wouldn't start and alarms went off continuously for over 2 hrs.
Had to be towed to nearest Chrysler dealership 30 miles away. Ignition miss, intermittent. Replaced spark plugs, problem resolved. Told to rtn to top up and if I do so for a third time, dealer to contact Chrysler Canada. Told a tear down might be required. Replaced heater core. While refueling, the valve would malfunction and allow liquid fuel to spit back out of the filler neck. Replaced fuel tank assembly.
I did not see any sign of leakage on the ground. Sometimes starter will not engage and other times it works just fine and starts right up. Does not seem to be the battery, starter, or key switch from what we can tell. It's sporadic and very hard to detect. Having trouble recreating the problem while in the shop.
Smoke test revealed gas cap bad, replaced again. Check engine light back on gas cap light back on same omissions code.Autos helped make these videos. We are still working to obtain content for your car, however the video above is believed to have similar characteristics as your car.
The engine in your Jeep Liberty should be running when you perform a transmission fluid level check, otherwise it will be inaccurate. The video above shows where the transmission fluid dipstick is located in your Liberty and how to check the transmission fluid level.
If the transmission fluid level in your Liberty is low, you need to add transmission fluid through the dipstick tube. When adding transmission fluid to your Liberty, be sure to add it slowly as it will fill up quickly and is difficult to remove excess fluid if you overfill. If you are having problems with the transmission in your Liberty, such as clunky shifting or hesitation, check the fluid level first - it is amazing how many drivers pay thousands of dollars for transmission work when a half quart of transmission fluid would have fixed the problem.
You love your kids right? See how to properly secure their car seat. If your brake fluid is a little low, learn how to add some here. Ignoring a low level leads to big problems. Getting Started Prepare for the repair. Open the Hood How to pop the hood and prop it open. Remove Dipstick Access point for transmission fluid.
Check Level Insert dipstick and pull it out to determine level. Add Fluid Determine correct fluid type and add fluid. More Info. Additional information on checking trans. Video Description. Other videos you might find helpful. Fix minor oil leaks Learn how to diagnose and fix minor oil leaks in your car Jeep Liberty Limited 3. Secure precious cargo You love your kids right? Add brake fluid If your brake fluid is a little low, learn how to add some here.
Ignoring a low level leads to big problems Jeep Liberty Limited 3. Replace fog lights Don't be caught in the fog with burnt out fog light bulbs Jeep Liberty Limited 3. The Right Parts. Full list of part and tools.
Download Jeep owners manuals.View unanswered posts View active topics. Moderator: KJs Moderators. It is currently Fri Apr 17, pm. Posted: Wed Sep 10, pm. So I took my Jeep to the dealer a few weeks ago because of an ongoing problem I've been having with my Jeep.
I've been having a problem getting the engine to start. I turn the key, nothing, not even a crank. History: First I thought it might be a battery, replaced it with a red top optima.
Didn't help. At this point I gave up and took it to the dealer, got a diagnosis of a neutral safety switch. Didn't let them fix it. Next I thought it could be the ignition switch, tested it Now my Jeep is in the body shop because of an accident.
I called that dealer back and argued with them that it can't be a neutral safety switch, because it doesn't have one. They told be it is not a NSS, but a solenoid inside the transmission. I said fine and hung up the phone. My FSM says its under the valve body.
I'm not very comfortable taking apart my transmission, so they transferred me over to the service department. I'm waiting for them to call back with a quote. Question is has anyone here need to replace this part and is it hard? Should I let the dealer do it? Should I try doing it? Should I take it to a local transmission shop? I'm still questioning that it could be this part. Forgot to mention that I have a P code. I had the valve body out of my 45rfe when doing the shift kit. It was a pain but it's doable.
If i'm not mistaken the solenoid pack just bolts to the vavle body. If it were mine i would either disable it or just throw it in neutral every time to start it. What you have going on is a pretty good anti theft system. Does that sound right? If it is in fact the TRS, should the engine start in neutral?
I'm a liitle confused! The Transmission Range Sensor TRS is part of the solenoid module, which is mounted to the top of the valve body inside the transmission.