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- Symptoms Without Summary
- Car Leaking Coolant
- AC Isn't Cooling
- AC Blowing Hot Air
- Shaking While Driving
- Overheating AC
- AC Smells Like Vinegar
- Heater Not Working
- Windshield Wipers Don't Work
- Car Leaking Water
- Car Leaking Red Fluid
- Car Battery Leaking
- AC Only Work Sometimes
- Shaking While Idle
- Shaking At High Speeds
- Evap System Leak
- Shaking While Braking At High Speeds
- Shaking When Stopped
- Shaking When Accelerating
- Radiator Leaking
- Pink Fluid Leaking
- Car Leaking Oil
- AC Not Working.
- Car Leaking Gas
- Power Steering Fluid Leak
- Bad Brake Caliper
Hey, Why is My Transmission Warning Light on?
If you are short on time and want to fast-track the process to professional help, click Yes
Is your transmission warning light on?
The transmission light indicates low transmission fluid, probably due to fluid loss, which can cause overheating. Less commonly, it can be internal damage in the transmission system, torque converter, or valve body.
If you notice the transmission warning light on your car's dashboard, paying attention and taking action as soon as possible is essential. This warning signal may indicate that something is not functioning correctly in your vehicle's transmission system, risking further damage if not addressed promptly.
It's essential to handle these issues before they get worse, as ignoring them can lead to costly repairs in the future. We recommend you review your car's symptoms to understand what's happening and possibly discuss it with a technician.
So don't be shy, pay attention to your car's quirks, and check out this article for all the info you need to communicate with your go-to auto shop and advocate for your car's needs.
Let's Get To The Bottom Of It!
- Automatic transmissions in modern vehicles use various control valves and sensors to keep the flu...read more
Automatic transmissions in modern vehicles use various control valves and sensors to keep the fluid and mechanical coupling between the engine and the drivetrain. These vital transmission components trigger an automatic transmission warning light when they fail. Sometimes, the warning has been going on for a while, indicating wear on transmission components. If the driver keeps driving the car regardless, it enters limp mode.
Limp mode is a safety feature that helps protect your car's transmission when it's at serious risk. It limits the speed and power of the vehicle, so you can still drive it, but you won't be able to go as fast or as strong. Think of it as a way for your car to limp to the nearest repair shop to avoid further damage.
It's plausible for computer software to receive false information and trigger the warning light. Still, keep track of shop-relevant symptoms like a stuck gear shift, the vehicle's inability to move, stalling, engine revs, and the inability to cruise control.
- The transmission fluid is vital to keep your shifts smooth and healthy. Among its duties, it cool...read more
The transmission fluid is vital to keep your shifts smooth and healthy. Among its duties, it cools down all the internal components inside the automatic transmission system, so they don't overheat. In addition, it also lubricates moving parts, reducing wear and tear. If this fluid is lacking, your transmission overheats faster and suffers further transmission damage.
If you notice a red fluid leak, burning oil smell, squealing sounds, high transmission fluid temperature, or a red check engine light on the dashboard, share these symptoms with the auto shop. These are critical indicators that they need to check.
- If your car is taking longer to shift between gears when accelerating or deaccelerating, it might...read more
If your car is taking longer to shift between gears when accelerating or deaccelerating, it might be having internal trouble. Typically, this happens when these components are wearing out and past service limits.
If you notice a lengthy gear shift time, longer startups, high engine temperature, or a red check engine indicator light on the dashboard, share these symptoms with the auto shop. These are critical automatic transmission failures that they need to check.
- If you're experiencing a shuddering or stuttering ride while driving, there could be an issue wit...read more
If you're experiencing a shuddering or stuttering ride while driving, there could be an issue with your car's torque control. This system helps power the wheels, keeping your vehicle running smoothly. The problem might be the torque converter, a fluid coupling between the engine and the drivetrain.
When the clutch that works with this part fails, it can cause the car to shift rough, as if it's unsure of which gear to use. It's essential to address this issue quickly because operating with this problem can cause damage to other parts of the transmission and make the repairs more costly.
- That's because there's an issue with a part of your transmission called the valve body. This valv...read more
That's because there's an issue with a part of your transmission called the valve body. This valve controls the flow of transmission fluid, ensuring it gets to the right places at the right time. But, when this valve isn't working correctly, it can cause the car to shift gears late or early, making hard noises. This can happen when insufficient transmission fluid, debris, or worn-out parts clog the valve, causing it to malfunction.
If you're having trouble getting your car out of park, requiring you to press harder on the brake pedal, tap it multiple times, or wiggle the gear shift. This could indicate a problem, and it's time to investigate and find the cause.
- Inside the transmission system, there are shifter interlocks that hold the shifting stick in plac...read more
Inside the transmission system, there are shifter interlocks that hold the shifting stick in place, preventing it from shifting out of "park" mode without the brake pedal active. This safety measure prevents your shift from getting into drive or reversing inadvertently. However, if this fails, it might lock the shifting gear unnecessarily, preventing you from moving it past the "park" position; A quick fix could be to bypass the shifter interlock switch.
If you notice a lengthy gear shift time, engine stalls, vehicle inability to go forward or reverse, engine revving, or a red check engine light on the dashboard, share these symptoms with the auto shop. These are critical indicators that they need to check.
Find Professional Help
Please select your vehicle's brand and location so we can locate the best professional help for youVehicle Health Inspection Proof
Explore the following typical inspection results that show a potential cause for the symptom and select the one you believe is similar to your vehicle's issue.
Low transmission fluid and overheating
Electrical failure
Internal transmission failure
Torque converter malfunction
Valve body issues
Shift interlock failure
The image shows the car's internal components. The red arrows are pointing toward leak spots in the transmission cooler lines, under the car's hood.
A customer dropped this vehicle off complaining about the yellow transmission light on the dashboard and a red "check engine" light. In addition, they said that, after checking the transmission fluid level, it was low; they also noticed some puddle leaks under the vehicle.
First, the technician performed a test drive, concluding that both afore-complained warning lights appeared on the dashboard. But, they cut the test drive short to avoid further transmission damage.
Then, while performing a vehicle health inspection, the technician concluded that the transmission fluid was low. In addition, they found a leak caused by a friction-damaged transmission cooler line. The leaking fluid was very dark.
To dive deeper into the issue, the customer allowed for additional inspection. The mechanic used a scanning tool to check the car's computer and found two problems. The first one was that the transmission was getting too hot, and the second one was that the gears weren't working correctly.
The mechanic replaced some transmission cooling lines to fix the problems and refilled the transmission fluid.
1/6
This image shows a wiring harness dirty by the transmission connector's leaks. This type of issue affects the transmission control module.
A customer came into the shop complaining that their car was performing weaker and wouldn't pass 25 miles per hour. In addition, they said that before the check engine and transmission lights popped on the dash, the car was driving well.
First, the technician did a test drive, verifying that the check engine and transmission warning lights appeared on the dash. They also noted that the vehicle was in limp mode, limiting the transmission to the 2nd gear and the rev limiter at 3000 rpm.
Moreover, a vehicle health inspection didn't lead to any new findings. So, the customer agreed to perform additional testing, revealing failures in the transmission control module and system. As it turns out, a code activated the car's safety limp mode, so the technician cleared all codes.
The additional tests didn't show a faulty connection or electrical components. So, the mechanic finally diagnosed the issue as a failed transmission control module (TCM).
2/6
This image shows debris and particles contaminating the car's transmission system; these are worrying signs and can progressively damage the vehicle.
A customer brought in their car because it wasn't shifting gears smoothly. They said that when the car shifted gears while driving, it would slow down, the engine revs would go up, and then it would finally shift gears after a few seconds.
The technician did a test drive, noticing the car's erratic gear-shifting behavior and engine revving. In addition, they also saw both the check engine and transmission warning lights on the dashboard.
During a vehicle health inspection, the mechanic noted that the transmission fluid was dark and produced a burnt smell.
The technician used a tool to check the car's computer and found that one of the sensors on the transmission was not working correctly; the output speed sensor. So they took the car for a test drive with two technicians, one driving and the other monitoring the transmission with the scanner.
They saw some worrying signs, so they removed the pan on the transmission and found a lot of debris and worn parts inside.
3/6
This image shows a scanning tool's monitor, which is an additional test instrument. The duty cycle and slip speed RPM values indicate transmission issues.
A customer brought in their car because it was making a strange shudder when going at a steady speed, but it would stop when they accelerated more. Apart from that, the car was driving normally.
During a test drive, the technician found the car displayed both the transmission and check engine lights. In addition, they noticed that the car would shudder when its torque converter should be locking up.
The torque converter is a fluid coupling transmitting torque from the engine to a rotating driven load. It transfers power from the engine to the wheels, allowing the car to change gears smoothly, and protecting the transmission from damage; a "bridge" between your engine and the transmission.
The technician did a vehicle health inspection that showed no relevant leads to the customer's complaint. So, the auto shop got authorization to perform a more in-depth testing procedure.
The technician used a tool to check the car's computer and found the converter clutch system malfunctioning. So they took the car for a test drive with two technicians, one driving and the other monitoring the transmission with the scanner.
The results indicated that the car's computer told the torque converter to lock up. When the convertor was supposed to be locked, the RPMs did not change. This failure was also causing a drop in fuel mileage, likely due to a faulty torque converter.
4/6
This image shows a valve body. The red arrow points toward a stuck solenoid; rust and wear signs surround the solenoid. The computer sends a signal to the solenoid to move, but the valve is not changing position. This indicates that the internal transmission requires repair.
A customer came in with their car and said that it feels like it's in two gears at once when it shifts gears. Plus, the gear-shifting was unusually hard.
The technician did a test drive, noticing both the check engine and transmission lights on the car's dashboard. Also, they verified that the car's transmission was hard shifting between first, second, third, and fourth gear.
They also performed a vehicle health inspection, revealing that the transmission fluid was very dark. But, since there were still underlying matters, the customer agreed to additional tests.
The technician used a tool to check the car's computer and found that both the shift solenoid "A" and "C" had "performance or stuck off" issues. So they took the car for a test drive with two technicians, one driving and the other monitoring the transmission with the scanner.
The results indicated a delay in the shift solenoids' transmission. So, the technician took out the transmission pan, discovering a lot of dark fluid. Finally, they flushed the transmission with a flushing solution, replaced the valve body, cleared codes, and filled the transmission. At last, the symptoms were gone.
5/6
This image shows a locked shift interlock. For the transmission to operate properly, the interlock should unlock when the engine is running and the brake pedal depressed. The red arrow points toward the faulty part.
A customer came into the shop complaining that their vehicle's transmission wouldn't get out of the "park" gear. Consequently, they had to ask for a tow.
During a test drive, the mechanic used a screwdriver to access the shift interlock system's bypass switch, to get the car into the "drive" gear. They already suspected the shift interlock system since the car wouldn't shift from the "park" mode.
But, after getting the car running, there were no driving issues. The customer agreed to additional testing.
After disassembling the shifter assembly, the technician measured to see if power was getting through the shift interlock; they found out that it was. Then, after manually depressing the shift interlock, the transmission moved out of the "park" mode.
Still, since this part comprises many other transmission components, the entire shifter assembly needs replacement.
6/6Typical Fixes to Address the Cause(s)
The following chapters bases themselves on experiences from our auto repair shop; we'll describe related problems' causes and fixes.
The AutoTechIQ ranking for Safety, Cost Avoidance, and Environmental Impact is
Vehicle Symptoms
Below are just a few examples of typical Symptoms and Fixes your car might be experiencing
Other things your auto repair shop might talk about:
Automatic gearbox systems. Gearbox warning light.