Shifting problems are tied to the transmission. If the car won’t shift gears, troubleshoot the transmission to find the answers. You will identify one or more of the following problems:
1). Transmission Control Module Problem
The transmission control module is vital to a car’s automatic transmission. It allows the engine to identify the correct time to change gears. A healthy control module delivers a smooth, seamless driving experience. What happens when it fails? The Nissan Altima will warn you by manifesting various concerning symptoms. For instance:
- Shifting down will become a challenge when you slow down.
- Shifting up will also become harder when you accelerate. This will create acceleration delays.
- The car may refuse to shift out of neutral.
- The gears will start slipping.
- You will observe shifting delays.
- The ‘Check Engine’ light will illuminate.
- The Nissan Altima’s fuel economy will suffer.
These symptoms point to a faulty transmission control module. A bad transmission control module is a threat to your safety. Fix it as soon as possible.
2). Dirty Transmission Fluid
Theodore W. Shelby from General Motors Corp noted in a paper that an automatic transmission is heavily dependent on a transmission fluid’s physical properties. His primary concern was the impact of low temperatures on automatic transmission fluid’s viscosity.
He would probably approve of the auto-transmission fluid heat exchanger recommended in this study from ‘Transactions of the Korean Society of Mechanical Engineers’ that aims to improve a vehicle’s fuel efficiency.
But as a layperson, your primary interest is the automatic transmission fluid’s level and the presence of various contaminants. Dirty ATF is a poor lubricant, which is problematic because the parts it should cool and lubricate will wear out at a faster rate.
3). Steering Wheel Issue
What if the vehicle refuses to shift from Park to Drive? You’ve pressed the button, but nothing is happening. Fidgeting with the shifter won’t solve the problem. Yes, you can probably force it out of Park, but from what your mechanic has seen, doing so may cause more damage.
You can blame the issue on the steering wheel. Apparently, locking the steering wheel to one side can interfere with the shifter’s work. Try forcing the steering wheel back to the other side. Make sure it can move freely.
If this fails to solve the problem, you have bigger issues on your hands. Take the car to a mechanic before things get worse.
4). Bad AT Selector Switch
How does the car know the gears in your Nissan Altima have shifted? An electronic sensor speaks to the ECM. In other words, a bad AT selector switch can prevent the car from shifting gears because it won’t signal the ECM.
5). Clutch Master Cylinder Problem
So far, this guide has assumed that your vehicle has an automatic transmission. But what if it uses a manual transmission? In that case, you can blame the clutch master and slave cylinders. These components can disrupt the hydraulic system once they fail.
Speaking of manual cars, you should also check the clutch. A worn-out clutch won’t let you change gears.
How To Fix Nissan Altima That Is Not Shifting?
Nissan Altimas that can’t shift is not only inconvenient but dangerous. Use the following solutions to fix them as soon as possible:
1). Ask The Mechanic
Leave this component in the hands of an expert. They will recommend repairs or a replacement after analyzing the situation. The experts at car treatments expect repairs to cost $300 or less, depending on the severity of the damage.
That figure jumps to $900 if you want a new transmission control module. That includes the labor fees. Some people argue against fixing transmission control modules. From what they’ve seen, you can’t even fix TCMs to begin with because manufacturers seal them.
This forces consumers to buy new units when the old ones fail. Dave Junior from My-Car-Makes Noise said the same thing. This is why licensed mechanics are so important. You need one to tell you whether repairs are even an option.
Just-Answer recommends a CAN Test. It will identify a communication problem between the control units in your car. But you need an advanced scanner.
2). Check The Transmission Fluid
Use a dipstick to check the transmission fluid’s level. Naturally, you should park the car and switch the engine off beforehand. If the fluid is low, add more. If the vehicle starts shifting gears as a result, don’t be so quick to celebrate.
You haven’t solved anything. Where did your transmission fluid go? Clearly, you have a leak somewhere. Take the vehicle to a mechanic. They can find and plug the leak before you lose even more transmission fluid.
What if the fluid is dirty? Replace it and the filter. The fluid should be light red or pinkish, not dark red or brown.
3). Fix The Shifter
- A mechanic will check the cable between the shifter handle and transmission, replacing it if the line breaks. The shifter can’t operate with a broken cable.
- The shift interlock solenoid prevents the car from shifting from Park to Drive unless you place your foot on the brake. A mechanic will replace a bad shift interlock solenoid. They can also repair or replace this component’s damaged wiring.
- If a worn-out ignition key tumbler locks the steering wheel, the mechanic will replace it.
- If the shifter mechanism is broken, the mechanic will replace it.
4). Move The Shifter From Park To Low
Common sense will tell a layperson to replace any electronic sensor that doesn’t work. But you have other options here. Move the shifter from Park to Low. Do this several times, but slowly. Why? If the switch’s contacts have corrosion, this procedure can remove it.
Otherwise, you should leave the car in a mechanic’s hands, preferably an expert specializing in transmission and electronic diagnoses.
5). Replace Clutch Master Cylinder
If the clutch master cylinder has a fault, replace it. The same goes for a slave cylinder and worn-out clutch. These components are easier to diagnose and replace than the selector switch and transmission control module because people are familiar with them.
Mechanics change clutch master cylinders and clutches all the time. You should also check the torque converter and gears. Gears can become damaged or misaligned. You should inspect the bearings and O-rings.
If it is not yet solved, you can watch this video!