Just like the engine, the transmission needs cooling to work properly. If your transmission overheats, it could suffer all kinds of damage. Fortunately, there’s a way to stay ahead of this issue. If your transmission registers a temperature that is out of spec, you’ll get a check engine light code on your dash with the P0218 fault code stored in the ECU.
Any fault code regarding the transmission should be addressed as quickly as possible, not just because you could be left stranded on the side of the road, but because the cost of repair can become extremely expensive. In some cases, you could need a completely new transmission.
In this article, we’ll be talking about the code P0218, what causes the transmission fluid to exceed max operating temperature, how to diagnose this problem, and how to fix the issue.
What is the P0218 Code, and What Does It Mean?
The P0218 stands for transmission over temperature condition. Put in simpler terms, it means that the transmission fluid exceeded the allowed maximum temperature (usually 290 °F) for a specific period of time. The ATF fluid temperature fluctuates depending on the circumstances. For instance, when you’re driving uphill, it’s normal for the temperature to go up in both the engine and transmission, but there are cooling systems that keep the temperature in check.
When the P0218 code is triggered it means that the transmission fluid cooling system isn’t working properly. This is a serious issue, and although there are safe modes that are likely to be triggered when this code appears in the ECU, it’s recommended that you stop the car as soon as possible.
What Causes a P0218
When it comes to the common causes of the P0218 fault code, there are a few things that trigger this code which include a faulty transmission fluid temperature sensor, low transmission fluid, a leak in the transmission system, internal damage to the transmission, but also things like towing an overloaded trailer.
Faulty Transmission Fluid Temperature Sensor
A faulty transmission fluid temperature sensor is a pretty common cause for the P0218 fault code, especially if there’s no transmission fluid visible under the car. When this sensor doesn’t work properly, it will send faulty readings to the ECU, and will likely cause the over temperature error to pop up.
Low Transmission Fluid
Although it’s not as common as a faulty transmission fluid temperature sensor, low transmission fluid can trigger the P0218 fault code. Without proper lubrication, the friction between the transmission components will lead to overheating, no matter if the rest of the transmission cooling system works as it should.
There are two main reasons why you might be dealing with low transmission fluid. The first one is that not enough transmission fluid was added to the system during regular maintenance, and the second one is that there’s a leak somewhere within the system. The transmission fluid won’t usually evaporate on its own.
Leaky Transmission System
A leaky transmission system is another common cause for the P0218 code, especially in older cars. There are a few parts to blame here that include the transmission fluid pan, transmission cooler lines, transmission radiator, or cooler. Note that cars have either a transmission cooler or a transmission radiator, but rarely both.
When there’s a leak in the system, there won’t be enough fluid which will lead to overheating and triggering the P0218 code.
Faulty Internal Parts of The Transmission
Every transmission uses high-precision parts that provide optimal performance. As soon as one part of the transmission is out of spec, it will cause additional friction between parts that will quickly cause overheating.
Faulty internal parts can cause much more damage than just overheating. If a part breaks inside the transmission, it can cause irreparable damage that will require you to get another transmission altogether.
Towing an Overloaded Trailer
Towing an overloaded trailer can cause the transmission to overheat. In some cases, people tow more than their car is able to pull. Combined with a lot of uphill driving, it’s only a matter of time before the engine and transmission being to overheat.
To prevent this, avoid going over your vehicle’s maximum towing capacity. If you need to tow something heavy, it’s better to rent a U-HAUL than to deal with rebuilding, or possibly replacing a transmission.
How to Diagnose and Fix P0218 Code
Diagnosing the P0218 code, or any fault code for that matter starts by scanning the ECU with an OBD II scanner. The code should be stored in the ECU, but because other codes can narrow down the diagnostic process, it’s best to check this first.
Visually inspect the transmission by looking under the car and searching for a possible leak. You’ll need to lift your car to do this and make sure it’s safe before you start checking for leaks. Finding one or more leaks will narrow down the parts you’ll need to replace in order to avoid finding the P0218 code again in your ECU.
After checking for fault codes, and leaks, you’ll need to check the transmission fluid and its condition. The fluid shouldn’t have a burning smell to it, and there shouldn’t be a lack of transmission fluid. The burning smell indicates that there’s a problem with the internal parts of the transmission, while low transmission fluid tells you there’s a possible leak somewhere within the system.
The last thing you’ll need to check is the transmission fluid temperature sensor. This over temperature DTC can be triggered by one or more of these issues, so covering everything will save you time and money in the long run. If the sensor is faulty, you’ll need to replace it with a new one.
Can You Drive With an Overheating Transmission?
If your transmission is overheating, and you find the P0218 code stored in the ECU, you really shouldn’t be driving your car. Most modern vehicles have a fail-safe mode that will prevent the car from even starting, or it will engage a built-in limp-mode to prevent any further damage to the system.
Even if you’re able to start the car and the ECU doesn’t trigger a fail-safe mode, you should avoid driving until the issue is fixed because driving the car with the P0218 fault code can cause more damage to the transmission which is one of the most expensive parts of any car.
Use Only Quality Parts!
Aside from the car’s engine, the transmission is the most important system of any car. When fixing the P0218 issue, it’s imperative that you use genuine, OEM, or high-quality aftermarket alternatives because anything else will put you at risk of dealing with more transmission issues down the road. For this reason, eEuroparts.com offers a wide variety of quality replacement parts for most European vehicles available in the US.
By choosing your car using the vehicle selection tool, you’ll get filtered results that include parts that are a guaranteed fit for your car. Whether you need a sensor, transmission pan, or fluid, we have you covered!
