What is OBD-II Code P245D – EGR Cooler Bypass Control Circuit High Bank 1

What is OBD-II Code P245D – EGR Cooler Bypass Control Circuit High Bank 1

As a mechanic, one of the things that I get asked about frequently is OBD (On-Board Diagnostics) codes. Most people don’t understand what these codes mean, and some of them can be pretty intimidating when they first see them. That’s why I’m writing this article, to explain what one of the most common codes – P245D – means, and how to fix it. Specifically, we’ll be talking about the EGR (Exhaust Gas Recirculation) Cooler Bypass Control Circuit High Bank 1. So, let’s get started!

What is an EGR Cooler Bypass Control Circuit High Bank 1?

The EGR Cooler Bypass Control Circuit is responsible for regulating the coolant flow to the EGR cooler. The EGR cooler is an essential part of an emissions system in modern vehicles. This system works by re-circulating some of the exhaust gas back into the engine to reduce emissions.

When the engine is running at certain conditions, the coolant is supposed to flow through a bypass circuit and into the EGR cooler, where it cools the exhaust gasses before they are re-circulated. If there is a malfunction in the system that regulates the coolant flow, then the EGR cooler might not be getting cooled properly. This can lead to a build-up of heat, which can cause damage to the engine and other components of the vehicle.

When the EGR Cooler Bypass Control Circuit is operating outside of its normal parameters, the OBD-II system detects this and triggers the P245D code. Specifically, this code indicates that the EGR Cooler Bypass Control Circuit for Bank 1 is operating at a higher level than it should be.

What are the symptoms of a P245D code?

There are a few different symptoms that you might notice if your vehicle has triggered a P245D code:

1. Check Engine Light: This is the most obvious symptom. When your vehicle encounters a problem that triggers a code, the check engine light will illuminate on your dashboard. If the P245D code is triggered, then you’ll see that light come on.

2. Lack of Power: The EGR system plays an important role in engine performance. If the EGR cooler isn’t working properly, then you might notice a decrease in power when you accelerate or climb hills.

3. Rough Idling: The EGR system can also affect idle quality. If the system isn’t functioning correctly, then you might notice a rougher idle when you come to a stop.

4. Fuel Economy: A malfunctioning EGR system can also impact fuel economy. You might notice that you’re getting worse gas mileage than usual.

How do you fix a P245D code?

Fixing a P245D code can be a little bit tricky, as there are a few different things that could be causing the problem. Here are some steps that you can take to diagnose and fix the issue:

1. Inspect the EGR Cooler Bypass Valve: The first thing that you should do is inspect the EGR cooler bypass valve. This valve is responsible for regulating coolant flow to the EGR cooler. Sometimes, the valve can become stuck or malfunction, which can cause the EGR cooler to overheat. If the valve is stuck, then you can try tapping it with a hammer to free it up. If that doesn’t work, then you might need to replace the valve.

2. Check the EGR Cooler: You should also inspect the EGR cooler itself. Make sure that it’s not clogged or damaged. If it is, then you’ll need to replace it.

3. Inspect the Coolant System: The problem might not be with the EGR system itself, but rather with the coolant system. Make sure that the coolant is flowing properly and that there are no leaks or clogs in the lines.

4. Check the Wiring: The EGR Cooler Bypass Control Circuit is controlled by a series of wires and connectors. Check these connections to ensure that they’re clean and aren’t damaged. Also, check that the wires aren’t shorting out.

5. Replace the Control Module: If you’ve tried all of the above steps and still can’t find the problem, then it might be an issue with the control module itself. You might need to replace this component to fix the issue.

Frequently Asked Questions:

1. Are P245D codes safe to drive with?

It’s generally not recommended to keep driving a vehicle with a P245D code. This issue can cause damage to the engine and other components of the vehicle.

2. Can I still pass an emissions test if I have a P245D code?

No, you will not pass an emissions test if your vehicle has any codes stored in the OBD-II system. You will need to fix the issue before the vehicle is retested.

3. How much does it cost to fix a P245D code?

The cost of repairing a P245D code can vary greatly, depending on what’s causing the issue. Simple repairs like replacing a valve or cleaning a line might only cost around $100, while more complex issues could run into the thousands.

4. Can I fix a P245D code myself?

If you have the proper tools and technical knowledge, then you might be able to fix the issue yourself. However, if you’re unsure, then it’s always best to take your vehicle to a professional mechanic.

5. How can I prevent P245D codes from occurring?

The best way to prevent P245D codes from occurring is to perform regular maintenance on your vehicle. Make sure that you’re changing your oil and filters regularly, and that you’re inspecting your coolant system and EGR system for any signs of wear or damage.


While the EGR system might seem like a complicated and intimidating part of a modern vehicle, it’s actually a pretty simple system once you understand how it works. If your vehicle has triggered a P245D code, then it’s important to take the time to diagnose and fix the issue, as it could potentially cause serious damage to your engine. Remember, if you’re unsure about how to fix the issue, then it’s always best to take your vehicle to a professional mechanic. They’ll be able to diagnose the problem quickly and accurately, and get you back on the road in no time!


If you’re interested in learning more about how the EGR system works, or about other common OBD-II codes, then there are plenty of resources available online. Here are a few good places to start:

– OBD-Codes.com: This website offers a comprehensive guide to all of the OBD-II codes, as well as tips for diagnosing and fixing different issues.

– AutoZone.com: AutoZone is a great resource for DIY mechanics, as they offer a wide range of tools and auto parts, as well as free repair guides and diagnostic assistance.

– YouTube: There are plenty of great YouTube channels out there with instructional videos on automotive repair and maintenance. Some good channels to check out include EricTheCarGuy, ChrisFix, and Scotty Kilmer.

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