P0571 Cruise Control/Brake Switch A Circuit Malfunction
OBD-II Trouble Code Technical Description
Cruise Control/Brake Switch A Circuit Malfunction
What does that mean?
This is a generic powertrain diagnostic trouble code (DTC) and typically applies to OBD-II vehicles. Vehicle makes may include but aren't limited to Chevrolet, GMC, VW, Audi, Dodge, Jeep, Volkswagen, Volvo, Peugeot, Ram, Chrysler, Kia, Mazda, Harley, Cadillac, etc.
The ECM (engine control module), among many other modules, don't only monitor different sensors and switches involved with the proper functionality of the engine but they also make sure to keep our creature comforts up and running (e.g. cruise control).
There are numerous factors that can alter the speed of your vehicle while you are driving down the road. Some of the new adaptive cruise control (ACC) systems actually adjusts vehicle speeds according to surroundings (e.g. passing, slowing for traffic, lane departure, emergency maneuvers, etc.).
That is beyond the point, with this fault, they are referring to the cruise control/brake switch "A" circuit malfunction. The proper operation of the brake switch is integral in the operation of your cruise control system. Given the fact that, one of many ways to disable or turn off cruise control is to depress the brake pedal, you will want to take care of this. Especially if you use cruise control in your day-to-day commuting. The letter designation in this case -- "A" -- may be referring to a specific wire, connector, harness, etc. To determine which one this code refers to, you will need to check out the appropriate manufacturer-specific service manual. If you are having a hard time finding what you need, it's always a good idea to look for a wiring diagram for the cruise control system. These diagrams, a lot of time, can provide you with valuable information (sometimes location, specifications, wire colors, etc.)
The P0571 Cruise Control/Brake Switch A Circuit Malfunction and related codes (P0572 and P0573) are set when the ECM (engine control module) detects a malfunction within the cruise control/brake switch "A" circuit.
Example of a brake switch and it's location:
What is the severity of this DTC?
Usually, with cruise control systems, I would say severity is set to low. But in this case, I will go with moderately-severe. The fact that there is a possibility of this fault causing the brake switch to malfunction, or vice-versa, is a significant concern.
One of the other functions of your brake switch is to provide the signal to turn on your rear brake lights to inform fellow drivers of your deceleration/braking. Having said that, it's operation is pretty important when overall driver safety is considered.
What are some of the symptoms of the code?
Symptoms of a P0571 diagnostic code may include:
Cruise control completely inoperative Erratic cruise control operation Certain functions not operating as they should (e.g. set,resume, accel., etc.) Cruise control turning on but not engaging No brake lights if the brake light switch is faultyWhat are some of the common causes of the code?
Causes for this P0571 cruise control code may include:
Cruise control/Brake switch defective Wiring issue (e.g. pinched on brake pedal, chafed, etc.) ECM (engine control module) issue (i.e. internal short, open, etc.) Debris/dirt mechanically hindering brake switch operation Brake switch not adjusted properly Brake switch out of it's mountWhat are some P0571 diagnostic and troubleshooting steps?
The first step in the troubleshooting process for any malfunction is to research the Technical Service Bulletins (TSB) for known issues with the specific vehicle.
Advanced diagnostic steps become very vehicle specific and may require the appropriate advanced equipment and knowle
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