What causes check transmission light to come on?
The check transmission light is one of the most important warning indicators on your vehicle's dashboard. When it illuminates, it signals that there may be an issue with your car's transmission system. Ignoring this light can lead to costly repairs or even complete transmission failure. In this article, we’ll explore the common causes behind the check transmission light and what you should do if it comes on.
1. Low or Contaminated Transmission Fluid
Transmission fluid is essential for lubricating and cooling the components of your transmission. If the fluid level is too low or the fluid is dirty and contaminated, it can cause the transmission to overheat or malfunction, triggering the check transmission light. Regularly checking and replacing your transmission fluid can help prevent this issue.
2. Faulty Transmission Sensors
Modern vehicles rely on sensors to monitor the performance of the transmission. These sensors send data to the car’s computer system, which uses the information to ensure smooth operation. If a sensor malfunctions or fails, it can send incorrect signals, causing the check transmission light to activate.
3. Transmission Overheating
Overheating is a common cause of transmission problems. This can occur due to heavy towing, driving in extreme heat, or insufficient transmission fluid. When the transmission overheats, it can lead to internal damage, which may trigger the warning light.
4. Slipping Gears
If your transmission is slipping out of gear or struggling to stay in gear, it’s a sign of a serious problem. This could be caused by worn-out components, low fluid levels, or other internal issues. The check transmission light often comes on to alert you to these problems.
5. Electrical or Computer Issues
Modern transmissions are controlled by complex computer systems. If there’s an issue with the transmission control module (TCM) or other electrical components, it can cause the check transmission light to illuminate. This might require a diagnostic scan to pinpoint the exact problem.
6. Mechanical Failures
Mechanical issues, such as a failing torque converter, damaged gears, or a broken transmission belt, can also trigger the warning light. These problems often require professional inspection and repair to prevent further damage.
What to Do When the Check Transmission Light Comes On
If your check transmission light comes on, follow these steps to address the issue:
- Check the transmission fluid: Ensure the fluid level is adequate and that it’s not dirty or burnt. If it’s low, top it off with the correct type of fluid.
- Pay attention to symptoms: Notice any unusual noises, slipping gears, or difficulty shifting. These can provide clues about the underlying problem.
- Drive cautiously: Avoid heavy acceleration or towing until the issue is resolved. If the light is flashing, stop driving immediately and seek professional help.
- Schedule a diagnostic check: Visit a trusted auto repair shop, like Kevin’s Autos, to have your vehicle inspected. A professional mechanic can use diagnostic tools to identify and fix the problem.
Conclusion
The check transmission light is not something to ignore. It’s your car’s way of telling you that there’s a potential issue with the transmission system. By addressing the problem promptly, you can avoid costly repairs and ensure your vehicle remains safe and reliable. At Kevin’s Autos, we specialize in diagnosing and repairing transmission issues. Contact us today to schedule an appointment and keep your car running smoothly!
Frequently Asked Questions
Can I still drive with the transmission light on?
We strongly advise against driving with the transmission warning light on, because it indicates there is a problem within the transmission system. Therefore, if you continue to drive, this could pose a safety risk, cause further damage, and leave you with a costly repair bill.
What are signs of transmission failure?
- Symptoms of a failing transmission:
- Slipping
- Delayed or harsh shifting
- Refusal to shift at all
- Refusal to shift when hot
- Refusal to shift when cold
- Vibration (damaged torque convertor clutch)
- Whining sound from pump
What triggers transmission light?
The transmission warning light (or message) indicates there's a problem with your car's automatic transmission or associated components. Some of the most common triggers of a transmission warning light are low transmission fluid levels, overheating, and internal transmission failure.
Will disconnecting battery reset transmission?
Disconnecting the battery cable for a short period will not fully reset your ECU because residual power remains in the circuits. If you want to perform a full reset, wait at least 15 minutes before reconnecting the battery to ensure all residual power has been drained.
How much does it cost to fix a transmission?
Average transmission repair costs range from $300 to $1,400. For example, if your manual transmission needs a new clutch, you can reasonably expect to pay around $800 to $1,500. On the other hand, transmission replacement is one of the most expensive repairs you can get. Replacements can range from $1,800 to $3,400.
Can a bad battery cause transmission light to come on?
Yes, it is possible to have transmission issues with a weak battery on some vehicles. A weak battery (or low voltage, more specifically) can cause delays or slipped gears when shifting, and even cause the transmission control module to enter a fail-safe state, forcing the car to limp home or to a shop.
What sensors can cause transmission problems?
A car has two speed sensors: the ISS and the OSS, working together to show the transmission data to the car's powertrain module. The ISS sensor monitors the input shaft's speed. If these sensors get misaligned, the operation of the transmission system will be affected.
What can be mistaken for transmission problems?
Common Automotive Misdiagnoses – 10 Engine Problems That Get Misdiagnosed As Transmission Failures
- Oil leaks.
- Faulty spark plugs.
- Engine misfire.
- Fuel delivery problems.
- Clogged catalytic converter.
- Faulty speed sensor.
- Broken temperature sensor.
- Malfunctioning interlock switch.
What are symptoms of low transmission fluid?
If your gears are slipping, it's a clear sign your car's running low on transmission fluid. When experiencing sudden up and down shifts, high RPMs right before shifting, or erratic shifting, seek assistance from your local service center to prevent your transmission from overheating or becoming damaged.
Why would the check transmission light come on?
If you're driving an automatic and this light pops up, it likely signals low transmission fluid levels, internal transmission failure, shift interlock problems, or overheating. These aren't just important reminders; they're vital for your car's health and your safety.
