The transmission control module is one of the most important parts for cars with an automatic transmission. There are only a few things that can go wrong with it, and one of the issues is followed by the P0613 check engine light code. Any problem with the transmission or TCM should be considered a very serious issue. It requires immediate attention to prevent additional damage and repair costs.
In this article, we’ll cover some basic information about a transmission control module, what causes the P0613 fault code, the symptoms, how to diagnose the issue, and how to fix it.
What Is The P0613 Code, And What Does It Mean?
The P0613 fault code stands for a malfunction detected in the transmission control module. Amongst European vehicles, it’s most common in Audi.
What this means is that the automatic transmission in your car may not work properly and can lead to additional damage if not addressed quickly. If you happen to find the P0613 code stored in your car’s ECU, it’s best to tow your car and fix the issue before driving it again.
Note that the P0613 fault code indicates an issue with the transmission control module, not necessarily the transmission itself. The mechanical part of the transmission may be in good condition, but if the control module doesn’t control the transmission as it should, it can end up causing damage to the transmission itself.
What Does a Transmission Control Module Do?
The transmission control module is a vital piece of any car that features an automatic gearbox. This module monitors speed, RPM and calculates the exact moment when the transmission should shift gears.
Its function directly affects how the car drives and what kind of driving experience you’ll have. Aside from this, the transmission control module is responsible for sending fault codes to the ECU once an issue is detected. The P0613 code is sent when there’s a problem with the transmission control module itself.
What Causes a P0613
Just like any other fault code, there are a few common causes for the P0613. These include faulty or loose electrical wiring, faulty or corroded connectors, a programming error in the transmission control module, or a defective TCM.
Programming Error in the TCM
A programming or software issue can’t occur on its own without the TCM losing power. Because people try to solve certain problems by disconnecting the battery, it’s not surprising that many electrical components fail. This can also happen with the TCM, which will eventually cause the P0613 code to appear.
Defective TCM
A defective transmission control module isn’t a very common cause for the P0613 fault code because it doesn’t fail often unless someone has messed with it previously. For a TCM to fail, there has to be a good reason – it can be humidity, shorted wiring, or in some cases bad aftermarket ECU/TCM upgrades.
Loose Electrical Wiring
Although most people think that loose wiring is the most common cause for the P0613 code, it’s not. The wiring isn’t exposed to extensive heat cycles like wiring that goes to and from sensors located on the engine block, but it’s exposed to engine vibration. Vibration can loosen up electrical wiring and cause the P0613 code.
Faulty or Corroded Connectors
Faulty or corroded connectors can cause the P0613 fault code but mostly in older cars. Modern connectors are usually well isolated and aren’t exposed to humidity and extensive heat, but this doesn’t mean that the connectors can’t corrode or become faulty.
The material from which the connectors are made deteriorates over time, which is why this is more common in cars that are 10 years old or older.
What Happens When a Transmission Control Module Goes Bad?
When the transmission control module goes bad, you can expect a few clear symptoms and the check engine light to come up on the dash.
Common symptoms include unstable or sharp shifting, issues with the speedometer, reduced fuel economy, or the transmission being stuck in neutral or first gear.
Check Engine Light
With any issue that stores a code in the ECU, the check engine light is the first symptom drivers notice. Unfortunately, it doesn’t point out the exact issue on the dash, so you’ll need to use an OBD II scanner to read the stored codes.
Unstable or Sharp Shifting Patterns
When the TCM stops working properly, the transmission will stop working properly. This doesn’t mean that the transmission will seize up, but it will likely shift gears when it shouldn’t and the transition between gears won’t be smooth.
This symptom can be especially dangerous if it happens at the wrong time – while trying to overtake or when you’re going uphill. The transmission may refuse to go into a higher or lower gear which can leave you having difficulties moving the car at all.
Reduced Fuel Economy
Reduced fuel economy is an expected issue if the transmission control module doesn’t work the way it should. When in good condition, the TCM adjusts shifting for optimal fuel economy, and even a slight difference in shifting time will have an effect on fuel economy. If the engine revs higher, the engine will use more fuel.
Transmission Stuck in Neutral or First Gear
Another common symptom of the P0613 fault code is a stuck transmission. Theoretically, it can get stuck in any gear, but most commonly happens in neutral or in first gear. If this happens, the only thing you can do is tow your car until the P0613 code is fixed.
How To Diagnose And Fix P0613 Code
Unfortunately, the P0613 code is amongst the most complicated codes to diagnose, especially because it’s commonly followed by other fault codes. Make sure to look up information regarding your car’s specific year, make, and model because technical service bulletins usually help solve complicated issues such as this one.
The first step in diagnosing the P0613 fault code is reading the stored codes in the ECU. This is done by using a standard OBD II scanner. It’s common to find other TCM codes as well, which should be repaired before attempting to diagnose the P0613 fault code.
When the P0613 fault code is the only one left stored in the ECU, visually inspect wiring and connectors for damage and corrosion. Also, make sure there are no blown fuses because they can be the cause of the issue as well. If you notice either a blown fuse or damaged wiring/connectors, you’ll need to replace them with an appropriate fuse or wiring/connector.
If fuses and wiring are in good condition, the next step would be to inspect the system controllers. You’ll need to check for excessive heat, collision damage, and water damage. Water is the most common cause of the transmission control module failure, so if you notice any water inside the controller, consider the controller defective. Only replacing the entire TCM will solve the problem with the P0613 fault code, but it will need reprogramming. In some cars, it can be done only by certified services or dealers. For some vehicles, there are aftermarket reprogrammed controllers that will work just fine.
Lastly, if the controller doesn’t seem to have any physical damage, it’s likely there’s a software issue causing the CEL. To fix it, you won’t need to replace the control module, but you will still need to reprogram it.
Can You Drive With A Bad Transmission Control Module?
When there’s a problem with the transmission control module, it can manifest symptoms in different ways. Even if there’s a slight delay in shifting, it can lead to complete transmission failure, which is a much more expensive fix than replacing the transmission control module. Because of the severity of the issue, it’s not recommended to drive a car with a faulty TCM and the P0613 fault code.
Why It’s Important To Use Genuine or OEM Parts ToFix The P0613 Code
The P0613 code is considered a severe issue, and fixing it sometimes requires reprogramming or replacing the entire control module. Because this part has such an important role in the way a car drives, it’s imperative to use high-quality replacement parts. We at eEuroparts.com offer a catalog of high-quality genuine, OEM, and quality aftermarket parts for most European vehicles, including TCMs.
Finding the right part for your car is simple. All you need to do is use the vehicle selection tool on our website. Select the year, make, and model of your car, and you’ll get a list of parts that are made specifically for your vehicle. This eliminates the possibility of ordering parts that won’t fit your car or won’t provide the required functionality.
