How To Fix 6.7 Cummins Exhaust Brake Not Working? Problems and Their Solutions

The exhaust brake is essential for a safe drive. It protects you from going too fast downhill. You get assistance to keep you safe on rough roads.  It may be risky if the exhaust brake is not working. If the case is like that, you need to find the causes and fix the issue. But what are the possible causes and solutions? 

When you have a problem with your 6.7 Cummins exhaust brake, you must check for several things. Some of the major culprits for exhaust brake not working can be:

• Blown fuses
• Faulty Relay
• Disconnected or damaged wires
• Problem with ECU connector
• Problem with the continuity system

It will be simple to fix the problem if you have identified why the 6.7 Cummins exhaust brake is not working. Stay tuned and learn how you solve the problem.

When to Use exhaust brake 6.7 Cummins?

Exhaust brakes assist you in slowing down the vehicle without applying the wheel-mounted brake system. You can take exhaust brake assistance to slow your vehicle speed at different times.

• Use the exhaust brakes when going downhill; it will protect you from going too fast.
• Exhaust brake also helps you control your vehicle while going up sloppy paths.
• When regular brakes stop working in emergencies, you can use exhaust brakes to stop or slow down the vehicle.

But remember, exhaust brakes are only effective when you have a slow speed. If the speed is too fast, you may not get effective results.

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Problems And Solutions To Fix 6.7 Cummins Exhaust Brake Not Working:

Fixing the exhaust brake not working problem will be easy if you follow the steps below. But make sure you have gathered all the required tools for assistance to complete the job.

Things you need:

• Screwdriver
• Multimeter
• Gloves
• Pliers

I recommend Testo 760-2 Digital Multimeter because it has excellent features but is affordable. Its major features are easy operation, reliable measurement, automation, and durability.

Here is a guide to fixing the problem quickly and perfectly. Please read the instructions carefully and apply them to get a solution to the problem.

Problem 1: Check for the Fuses

Blown or disconnected fuses can be the culprit for the exhaust brake not working. Fixing the fuses is cost-effective and simple. Lets’ see the ways how you solve this specific issue. 

• Remove the fuse box cover by unscrewing the screws. 
• Look under the hood on the driver’s side of the engine for the fuse box.
• Once you have removed the cover, check different fuses. 
• Remove the fuse and check its points and connectors. You do not need tools to remove fuses, simply pull out the fuse. 
• If you find any fuses are blown, replace them with new ones.

Problem 2: Inquire About the Relays

Faulty relays can cause the 6.7 Cummins exhaust brake not to work. The next thing to check is Cummins relays. Take pliers and remove the relay; the relay is also available near the fuses inside the fuse box.

Take out the relays one by one with the pliers and check their connectors. If you do not see any of the relay’s problems, check for the relay wires. Ensure no burnt wires are connected to the relay.

Problem 3: Inspect the Wiring System

Burnt or cut with the wires can make your exhaust brake not work. So ensure you have checked the wires and find them perfect. Checking the wires is simple; remove the fuse box and inspect the wires on the back.

Check the entire wires from start to end and ensure no wires are damaged or burnt. If you find the wire is damaged and needs repair, repair it or replace it for power continuity.

For confirmation of power supply to the electronic parts, use a multimeter. Connect the wires with the multimeter and confirms wires are supplying power correctly.

Problem 4: Check the ECU Connector

ECU connector is the major part that controls the electronic fuel injection system. So exhaust brake performance is directly connected with the ECU connector performance. If there is an issue with the ECU connector, you will be unable to get the performance of the exhaust brake.

ECU connector is located inside the dashboard near the engine. Take your screwdriver and remove the ECU compartment cover and inspect the connectors. 

Ensure all the connectors are delicate and there is no issue with them. If you find any connectors are bad or need replacement, replace them.

Problem 5: Inspect the Continuity System

The continuity system of your 6.7 Cummins plays a major role in exhaust brake performance. If the continuity system fails to perform its responsibility, you will be unable to use the exhaust brake.

The ECU connectors can check continuity. Check the information on the connector; you will find all the information about the continuity pin on the connector.  

Count the pins and insert the multimeter pin on the connector’s concerned pin. It may take some time; do not hurry; check it calmly.

Now go to the relays and connect the multimeter’s other pin to the concerned relay. Check the continuity and make sure the power is running correctly. Make sure the continuity system is working finely.

I hope you will resolve the problem. If it still exists, call the professional guy to identify the problem to solve the issue.

Frequently Asked Questions (FAQs):

My opinion:

Exhaust brake ensures a safer ride on smooth roads, but you may face the problem over time. Fixing the exhaust brake is no doubt a complex and time taking task. 

But it will be easy to have the correct tools and learn how to fix the exhaust brake. But ensure you have appropriately learned; otherwise, consider the paid professional services.