Transmission not shifting into overdrive

The transmission is not shifting into overdrive.
Experienced mechanics share their insights in answering this question :
Hello. If the transmission is shifting fine but will not go into overdrive, then it may have a solenoid failure or a pressure problem. A bad brake light switch can also cause this. I would typically start by checking to see if the brake light works. If they don’t or if they remain on, then I would replace the switch. If any of the previous issues mentioned are no the cause, then the transmission would need to be diagnosed. I would get some help from a certified mechanic, like one from yourMechanic, to replace the brake light switch and inspect any other possible issues.

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Possible causes of no overdrive include a faulty transmission range switch, valve body, faulty overdrive brake, or faulty ECM. Faults codes should be read out with a scanner, and statuses read.
Hi there. There are several potential reasons why the transmission on your 2002 Town & Country does not shift into overdrive. This could be caused by low transmission fluid, a blockage in the transmission lines, or a transmission sensor.
Symptoms of a bad overdrive switch:

Transmission won`t shift into overdrive. The driver is unable to disengage overdrive.

Too much torque demand during acceleration can cause the engine to bog or die. Too much torque demand during deceleration can damage the transmission and clutch.
With an automatic transmission, overdrive is most often an intuitive function initiated by the ECU when the vehicle reaches the proper speed. In the case of manual transmissions, overdrive is the highest gear of the transmission but has to be engaged by the driver.
There could be two things going on. The cruise control switch could be having a crossed wire or short inside it. The other problem is the transmission overdrive solenoid could be getting hot and causing the clutch to slip in and out of overdrive.
A failing transmission position sensor may no longer send the right signals to the Powertrain Control Module, or PCM. Without signals from the position sensor, the PCM will no longer know when to shift the transmission`s gears out of park into a moving gear. Transmission shifts into the wrong gear.
It`s not bad to drive with overdrive off and does no harm to the transmission. However, you will get worse fuel economy and have more noise at high speeds. There`s really no reason to leave it off unless you need to ascend or descend a steep hill. You can turn overdrive on or off at any time or speed.
Overdrive as a definition is simply having a faster transmission output shaft speed than the input rotation speed of the input shaft from the engine. This means torque is effectively being multiplied in a positive sense so being `overdriven`, creating a more effortless driving experience.
Transmission won`t engage or stay in gear

If when you put your vehicle into gear and it won`t move, this may be a problem with low transmission fluid due to a leak, the shifter, shifter cable, or it could even be a problem in the valve body of your automatic transmission.

Turn off your vehicle`s ignition and wait patiently for 5 to 10 seconds. Start the engine and allow it to idle for several seconds. Switch off the ignition and wait patiently for another 30 to 40 seconds. Repeat these steps 2 to 3 times in order to reset your vehicle`s transmission control module.
It`s not a good idea to tow while in overdrive on any road other than a flat one. The engine will be in a higher gear, providing less torque. The transmission will be overtaxed, using fewer revolutions per minute. As a result, the truck or RV will have more difficulty towing cargo uphill or downshifting to go downhill.
It`s not a good idea to tow while in overdrive on any road other than a flat one. The engine will be in a higher gear, providing less torque. The transmission will be overtaxed, using fewer revolutions per minute. As a result, the truck or RV will have more difficulty towing cargo uphill or downshifting to go downhill.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

The transmission keeps dropping out of overdrive.
ANSWER : Hi there. If the transmission is coming out of overdrive and back into overdrive, either the downshift solenoid has an internal leak or there is an internal issue with the transmission overdrive clutch. Check the downshift solenoid and see if it’s functioning. To do this, slow down the vehicle and see if the rpm’s slightly raise up as the vehicle descends to a stop. If the rpm’s are not raising up as the vehicle is slowing down, then I recommend replacing the downshift solenoid. If the rpm’s raise up, then there is an internal part failure in the transmission. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your transmission.

Transmission issues, rough shifting and noise
ANSWER : Many different faults can cause the vehicle to shift roughly. The most common would be low fluid level in the transmission, transmission mounts, the torque converter, or one of the shift solenoids. If you’d like to get this checked before moving forward with a repair, a qualified technician, such as one from YourMechanic, will be able to diagnose your shifting issue and perform any repairs required.

Transmission intermittently won’t shift to next gear
ANSWER : It is very possible that the transmission may require a full rebuild or a replacement in order for it to perform properly. Although you are able to shift into other gears, if certain gears are not working correctly, transmission damage may be the cause.

If the transmission has already been diagnosed by the dealer that it needs replacement and the transmission is still not shifting properly, it is unlikely that the transmission will get any better without replacement.

It does not hurt to attempt any reset procedure that may be available, but it is also unlikely that a reset of any kind will resolve transmission issues. Small things to check before replacing the transmission if possible would be the fluid level and any trouble codes that may have been stored due to the issue your transmission is causing.

If any codes exist, this may lead you to other possible parts inside the transmission that may be able to be replaced and have your transmission working again as it should. You can get a second opinion from an local expert, such as one from YourMechanic, in order to diagnose your shifting problem and advise you on the next steps.

07 charger v6 wont move, like its in limp mode, will shift solenoid fix this? wont move in reverse. thinking shift solenoid, help.
ANSWER : The check engine light could mean diagnostic codes related to the transmission failure are available. If you request a check engine light diagnostic a mechanic could see if relevant codes have set and narrow the diagnostic for you. Check to be sure that there is adequate fluid. Check to be sure that the manual lever (shift lever) on the transmission reaches the correct position when you select "D" or "R". If you can’t move in any gear, the problem is not likely to be the solenoids because failure of the solenoids will still allow operation in "some" gears, if the gear is manually selected. If the solenoids failed, such would also result in a code being output because the TCM performs continuous circuit integrity testing on the solenoids. You can test that part separately in any event. There is a 164 page repair manual, with all the diagnostics, that you can use to pinpoint and repair the issue. However, if you just want a diagnostic, you can request a transmission diagnostic – failure to shift and the responding certified mechanic will pinpoint the issue. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Kia Optima 2004 v6 LX new engine old transmission no problems before with transmission now my transmission is shifting a high rpm
ANSWER : Hi There,
This may be an issue related to the communication of the PCM and the TCM (Transmission control module). As you may know, the TCM relies on the PCM to transmit information related to RPM’s, which the TCM then uses to determine when to direct the transmission to shift. The transmission control module has various sensors such as vehicle speed sensors, wheel speed sensors, throttle position sensors, turbine speed sensor, and transmission fluid temperature sensors that all direct information to it in order for it to perform it’s function. Other functions controlled by the TCM are components such as a kick down switch, traction control system, and cruise control module. Any of these may also affect the way the transmission control module performs and controls the transmission and the shifting of your vehicle. I would suggest having a professional from Your Mechanic come to your location to properly diagnose your transmission problem.

Sometimes when I shift my car’s automatic transmission into Drive it stays in neutral. Reverse works and trans fluid is full.
ANSWER : It is very possible that you could have some internal transmission damage. I would recommend enlisting in the assistance of a qualified transmission professional to inspect your transmission for internal faults. I must warn that this could be a pricy inspection as it may involve the removal and disassembly of the transmission. However, this is a sure fire way to determine if any internal damage has occured. The good news is that if any damage has occured, it can easily be resolved at that time since the transmissoin has already been disassembled.

Transmission can’t shift, thinks it needs to be replaced
ANSWER : The best advise to help prolong the life of this transmission is to service it regularly. Make sure you also service the engine cooling system on a regular basis since the transmission cooler is in the radiator. If you are in a warm climate or tow on a regular basis, look into getting an additional external transmission cooler installed. The transmission will run cooler and have less chance of heat-related failures. I also recommend you have a check up on the transmission before any warranty expires. Service any new transmission for the first time at 20,000 miles and every 30,000 miles after that.

2003 jeep liberty stuck in reverse, shifter is stuck…but crawling under and trying to manually shift from transmission stuck
ANSWER : Hi there. Based on what you have written above, it is highly probable that the inner linkage has come loose or there is an obstruction within the inner gear set that is causing your problem. Unfortunately, this typically requires dropping the transmission and repair or inspection from the inside. This is not a service our mobile mechanics are equipped to offer, so your best bet is to contact a local transmission specialist for assistance.