Proper application of cruise control has become more than just a simple luxury. For many vehicle owners, cruise control allows them to save as much as 20% on fuel economy when driving on long-distance road trips. Others rely on cruise control to help relieve pressure on knees, leg muscles, and sore joints. However you use the cruise control on your vehicle, it is a hassle to fix it on your own.
One of the leading components that fails sooner than others is the cruise control brake release switch. The job of the cruise control brake release switch is to allow drivers to deactivate the cruise control by simply tapping the brake pedal. This switch is used on automatic transmission vehicles, while on most vehicles with a manual transmission there is a clutch release switch that cancels the cruise control once the clutch pedal is depressed.
Additionally, there is always a hand-operated button that deactivates the cruise control on the steering wheel or turn signal arm. Having multiple deactivating devices is mandatory for vehicles sold in the United States as it's an important safety feature.
There are several individual components that comprise the cruise control system that may cause the vehicle's cruise control to fail, but we'll assume that the proper diagnosis has determined that the brake switch is faulty and needs to be replaced. There are two common reasons why the brake switch may be faulty, both of which cause the cruise control to malfunction.
The first case is when the cruise control brake switch does not open, which means that when you press on the brake pedal it does not shut off the cruise control. The second case is when the cruise control brake switch does not close the circuit, which does not permit the cruise control to set. In either case, this requires a replacement of the brake pedal cruise control switch.
Note: The specific location and steps for removing this component may vary based on the vehicle you own. The steps below are general instructions. Make sure to verify specific steps and guidelines with your vehicle manufacturer service manual before proceeding.
Warning: Working on electrical equipment such as the cruise control brake switch can result in physical harm if you don't disconnect the power supply before attempting to remove any electrical components. If you don't feel 100 percent confident about replacing the cruise control brake switch or don't have the recommended tools or help, please contact an ASE certified mechanic to complete this job for you.
Part 1 of 3: Determining the symptoms of a bad cruise control brake switch
Before you make the decision to order replacement parts and remove the cruise control brake switch, it's always a good idea to properly diagnose the issue. On most OBD-II scanners, an error code P-0573 and P-0571 are typically the codes that indicate a problem with the cruise control brake switch. However, if you don't receive this error code, or don't have a scanner to download error codes, you'll have to do some self-diagnosis checks.
When the cruise control brake pedal switch is faulty, the cruise control will not activate. Since the brake pedal and cruise control share the same activation switch, one way to determine if the switch is faulty is to press the brake pedal and see if the brake lights illuminate. If they do not, the cruise control brake switch may need to be replaced.
Some of the other symptoms of a bad of faulty cruise control brake switch include:
Cruise control does not set: When the cruise control brake switch is damaged, it usually does not allow the electrical circuit to complete. This keeps the circuit "open," which essentially tells the cruise control that the brake pedal is depressed.
Cruise control will not shut off: On the opposite side of the equation, if the cruise control won't shut off when you press the brake pedal, it's commonly caused by a faulty cruise control brake switch that is closed, meaning it will not send the signal to deactivate through the relay and to the vehicle's ECM.
Cruise control shuts off automatically while driving: If you're driving down the road with the cruise control activated and the cruise control shuts off without pressing the pedal, there may be a malfunction inside the brake switch requiring replacement.
Part 2 of 3: Replacing the cruise control brake switch
After diagnosing that the cruise control brake switch is faulty, you'll need to prepare your vehicle and yourself to replace the sensor. This job is relatively easy to complete, as most brake switches are located under the vehicle's dashboard, slightly over the brake pedal.
However, since the location of this device is unique to the vehicle you're working on, purchasing a service for the specific make, model, and year of your vehicle is highly recommended. The service manual will typically give you the exact location along with several replacement tips from the manufacturer.
Materials Needed
- Boxed end wrench or ratchet wrench
- Flashlight
- Flat head screwdriver
- Thread locker
- Replacement cruise control brake switch
- Replacement cruise control brake switch clip
- Safety equipment
Step 1: Disconnect the vehicle's battery. The first thing that should be done before replacing any electrical component is to disconnect the power supply.
Locate the vehicle's battery and disconnect the positive and negative battery cables before proceeding.
Step 2: Locate the cruise control brake switch. After removing the power supply, find the cruise control brake switch.
Refer to your vehicle's service manual or contact a certified ASE mechanic to ask them where the brake switch is located for your specific vehicle if you have difficulty finding the unit.
Step 3: Remove floor mats from drivers side. You'll have to lay flat under the dashboard in order to remove and replace the cruise control brake switch.
It's a good idea to remove any floor mats as they not only cause discomfort but also may slip while you're working and potentially cause injury.
Step 4: Remove any access panels under the dashboard. On many vehicles the dashboard has a cover or panel keeping all wires and sensors contained and free from the brake and throttle pedals.
If your vehicle has this type of panel, remove it to gain access to the wiring harnesses underneath the vehicle.
Step 5: Disconnect the wiring harness attached to the cruise control brake switch. Remove the wiring harness that is attached to the sensor.
To complete this, you'll need to use a flathead screwdriver to carefully depress a white clip that connects the wiring harness to the sensor. Once you press down on the clip, pull on the harness slowly to remove it from the brake switch.
Step 6: Remove the old brake switch. Remove the old brake switch typically secured to a bracket with a 10mm bolt (specific size of the bolt will vary for each vehicle).
Using a boxed end wrench or ratchet wrench, remove the bolt carefully, keeping one hand on the brake switch. Once the bolt has been removed, the brake switch will become loose and should be removed easily.
However, there may be a secure clip attached to the back of the brake switch. If there is, use your flat blade screwdriver to carefully pry the clip off the fitting on the bracket. The brake switch should "pop" off easily.
Step 7: Compress the new brake switch clip to the new brake switch. Purchase a new brake switch clip (if your vehicle’s unit has one) instead of trying to reset and reattach the old clip to a new sensor.
In many cases, the clip is installed on the new brake sensor already. If not, make sure to secure the clip to the back of the sensor before attempting to reinstall the new unit.
Step 8: Reattach the cruise control brake switch. Make sure to reinstall the brake switch in the same direction as the previous brake switch.
This ensures the wiring harness is easily attached and the switch works correctly. If the brake switch has a clip, press the clip into it's fitting on the bracket first. It should "snap" into position.
Step 9: Reattach the bolt. Once the brake switch is properly aligned, reinstall the 10mm bolt that secures the brake switch to the bracket.
It's a good idea to use thread locker on that bolt as you don't want that brake switch coming loose. Tighten the bolt to the recommended torque pressure as noted in your vehicle's service manual.
Step 10: Inspect the wiring harness. Although many mechanics assume the job is done once the harness is reattached, in some cases, the wiring harness itself is the cause of the cruise control problems.
Before reattaching the harness, inspect it for loose fitting wires, frayed wires or wires that are disconnected.
Step 11: Reattach the wiring harness. Make sure you reattach the wiring harness in the same direction it was removed.
It should "click" into place once it's properly secured to the new cruise control brake switch. Step 12: Reattach control access panel under the dashboard. Install as it was when you started.
Part 3 of 3: Test drive the vehicle
After you've successfully replaced the cruise control brake switch, the issues should be fixed. However, you'll want to test drive the vehicle to ensure the original problem is resolved. The best way to complete this test drive is to plan your route first. Since you'll be testing the cruise control, make sure you find a highway with very little traffic in order to test the device.
If you were having problems with the cruise control shutting off after a certain period of time, you'll want to test the vehicle for at least that same time period.
Step 1: Start the vehicle. Let it warm up to operating temperature
Step 2: Plug in scanner. Make sure to plug in a diagnostic scanner (if you have one) and reset any error codes.
Once that has been done, complete a new scan and determine if new error codes show up before test driving.
Step 3: Drive at highway speeds. Drive your vehicle to the test highway and accelerate to highway speeds.
Step 4: Set your cruise control at 55 or 65 MPH. After the cruise control is set, slightly tap your brake pedal to verify the cruise control shuts off
Step 5: Reset the cruise control again and drive for 10 to 15 miles. Verify that the cruise control does not shut off automatically.
Replacing the cruise control brake switch is very simple once you have the right tools and know the precise location of the device. If you've read these instructions and still don't feel 100% confident in completing this repair, please contact one of YourMechanic’s local ASE certified mechanics to complete the cruise control brake switch replacement job for you.
