A car having transmission problems in cold weather is a very common issue. The main reason behind it is, that the low temperatures increase the viscosity of the transmission fluid and it doesn't flow smoothly in the system. This article talks about the various causes of this problem, how it affects the vehicle, and the methods that can be used to fix this issue.

Changing the fluid solves plenty of transmission issues but if the problem of automatic transmission won’t shift into 3rd gear persists, the parts you should check are the throttle cables. A defective cable with excessive slack is likely to create issues with smooth shifting of the gears. It may also totally stall the shifting. It could be a bad shift fork, or loose linkage, or it could be the 3-4 shift collar dogs sticking and not allowing the shift collar to slide back off of 4th gear. Either way, you’re probably going to have to remove the transmission from the vehicle and open it up to figure out what the problem is. Grinding or shaking sensation in gear Your automatic transmission normally operates smoothly when shifting from gear to gear. You shouldn't feel any grinding, slipping or shaking sensations as your car switches gears. When a transmission is starting to have problems, these symptoms can seem insignificant.

Step by step repair guide on how to troubleshoot and repair automatic transmission problems. This repair guide pertains to most vehicles.

Difficulty Scale: 4 of 10

Tools and Supplies Needed

• Flashlight
• Protective eyewear and gloves
• Code reader
• Shop towel

Diagnostic Procedure Before Repair

Step 1 - Clear all DTC's with a engine scan tool (diagnostic trouble codes.) Visit - Scan PCM

Step 2 - Start the engine and observe the MIL, if it does not illuminate continue to next step (service engine soon or check engine light.)

Step 3 - Drive the vehicle while trying to maintain a constant throttle position as it accelerates up through all four gears. If the transmission is shifting properly, it should be in 4th gear by the time you reach 45 to 50 mph on level ground. Repeat this procedure from a standing start 3 to 5 times. Rescan the PCM for trouble codes, if none appear the problem could have been a onetime occurrence. If a trouble code has returned repair as needed and recheck system.

Problem Guide

Will not go into gear:

Transmission Not Changing Gears

• Broken gear selector cable.
• Brake lock solenoid or brake light switch has failed not allowing the gear selector to move out of 'Park.'
• Excessively low transmission fluid (Note: If transmission is operated for an extended amount of time with a low fluid level the transmission might fail prematurely.)
• Shorted electrical component not allowing the PCM to control the transmission. Example: shorted fuse or VSS (vehicle speed sensor.)
• Flex plate (flywheel) is broken completely not transferring engine power to the transmission.

Goes into gear but fades out of gear or is slipping while driving:

• Transmission fluid is low.
• Transmission clutch discs or bands are worn out or burned.
• Faulty transmission shift solenoid.

Goes into gear but does not shift out of first gear:

• Blown fuse to the PCM controller
• Faulty vehicle speed sensor (VSS)
• Shorted second gear control solenoid
• Faulty transmission controller (PCM)

Tips and Fixes

• When the vehicle is cold or going around corners the transmission fades in and out of gear: In most cases this means the transmission fluid is low. The transmission will lose hydraulic pressure causing the transmission to drift in and out of gear. Check your transmission fluid when the car is on flat ground with the engine idling in park, (Some Chrysler products must be checked in neutral.)
• Transmission is shifting too late or not at all. On most cars the transmission is controlled by the PCM (powertrain control module) if the vehicle speed sensor fails the PCM has no input so the computer will not shift the transmission properly. The best way to check this sensor is to make sure the speedometer is operating correctly, if not replace the VSS and recheck.
• The transmission skips second gear, shifts from first gear to third gear and the 'service engine soon' or 'service engine soon' MIL is illuminated. Scan the computer to help locate the transmission control solenoid that is malfunctioning.

Fluid Level and Leaks

A common complaint with automatic transmissions is them leaking fluid. Leaks can occur from the output shaft seal, input shaft seal, pan gasket, fluid cooler or lines. When adding transmission fluid, do not overfill, doing so could cause the fluid to become aerated which will affect transmission operation.

If the fluid level is low with no visible leaks, check the radiator for fluid in the coolant. The cooler inside the radiator may be leaking and cross-contaminating the radiator coolant (the coolant will be milky pink.) Also check the condition of the fluid, some discoloration and darkening is normal as the fluid ages, but if the fluid is brown or has a burnt smell its badly overused and a transmission service is needed.

Most transmission problems can be prevented by changing the fluid and filter (if applicable) according to manufacturer specifications. In extreme conditions installing an aftermarket auxiliary cooler parallel can be installed furthering the cooling effect. This prevents fluid overheating on vehicles used for towing or performance applications.

Helpful Information

Automatic transmissions make specific noises when a malfunction occurs. An automatic transmission is a hydraulic pressure driven system that can make different noises than manual transmission problems. If the transmission filter becomes plugged due to debris, it can make a whirring noise. If the fluid level is low, you might hear a bubbling sound which is caused by the pump scavenging fluid inside the transmission pan. Most internal failures are due to bearing, clutch or hard part failure. When such a failure occurs the transmission can make a grinding, whirring sound or no noise at all. When a transmission has a major failure you might hear a loud pop which could mean a drive component inside the transmission has failed.

Best Practices

• Never allow little noises go unattended, a small noise can cause a transmission failure. Avoid overloading a vehicle or towing beyond capacity as this can cause premature failure.
• To prevent damage come to a complete stop before engaging park mode.
• Fault codes will be set when the transmission controller or PCM detects a malfunction. Codes are set by the computer when detecting malfunctions, such as a 2-3 shift solenoid that is not responding.

Any transmission is difficult to diagnose, however, there are differences between an automatic transmission and a manual transmission. The automatic in particular uses three different systems internally that work together, allowing the car to shift smoothly and automatically. 7 speed reading mac torrent. When there are issues with these systems and the internal parts, you may experience problems with the transmission shifting gears easily.

How an Automatic Transmission Shifts

There are three systems in an automatic transmission that work together for it to run correctly. These include the electrical, hydraulic, and mechanical systems. The transmission gets its signals to function properly from the Electronic Control Module. The ECM is the vehicle’s internal computer that helps shift the gears automatically.

The electronic sensors inside the transmission monitor the gear selection, speed, and throttle position. This includes a Control Module that adjusts the current provided to solenoids inside to control the gears. The hydraulic system is used to select gears dependent on the transmission fluid’s pressure applied. The mechanical system primarily helps with power at high speeds. In general, the automatic transmission reduces higher engine speed to the slower wheel speed so the torque increases while shifting to provide a smooth drive.

Is Your Automatic Transmission Working Correctly?

There are actions that work together to make your automatic transmission function the way it is supposed to. The ECM must be working right so that all signals sent from the computer allow for the vehicle to perform and shift effortlessly. If that signal coming from the Electronic Control Module is running good, then the appropriate hydraulic pressure will be given so the components of the transmission run as well.

All of these components that work internally to achieve a smooth shift must be in a mechanically sound working condition. There are some warning signs to look out for, which show if these components are not working and you may need a transmission repair. The following signs point to a failing automatic transmission:

• If the transmission fluid is low or dark
• You hear whining and loud grinding noises
• The gears do not shift from one to the other easily
• Or your car jerks while changing gears

If any of these are happening with your car, get it to a transmission repair mechanic as soon as possible.

Transmission Not Shifting Gears

Issues with the Transmission

Transmission Not Shifting Into Overdrive

One main reason why the automatic transmission in your car may not be shifting smoothly is the ECM is going bad. It is best to get this checked out by an experienced auto mechanic technician who understands the electrical system. Other indicators include bad connections within, or worn out sensors and faulty solenoids. All of these lead to what is called a “no shift” condition, making the transition between gears difficult or shifting gears impossible.

Transmission Not Shifting Out Of First Gear

This can be dangerous for an automatic transmission to experience these conditions while driving. Make sure to check a few parts if this begins to happen. You can look in the engine for worn, damaged or disconnected wiring, as well as blown fuses. Also, have a scan done at an auto repair shop if the check engine light comes for issues with the sensors. As always, make sure to check the level and state of the car’s transmission fluid according to your factory recommended maintenance schedule.

Transmission Not Shifting Properly

Visit a nearby AAMCO Minnesota location if your vehicle is having trouble shifting gears. You may need a Transmission Repair service on your car, so make sure to Schedule an Appointment as soon as possible before the automatic transmission goes out on you completely.