Cruise control not working

ANSWER : Hello. This can be caused by a number of different issues. Most of the time this is caused by a bad brake switch. If the switch is shorting out, then it will cause the computer to think that the brakes are being applied, which turns off the cruise control. If the switch is fine, then it may have a bad speed sensor or the cruise control switch itself is bad.

One of the easiest tests I do is simply have someone drive behind me and see if the brake lights are coming on without touching the pedal. If it is, then you should replace the switch. If not, then further testing of the circuit has to be done. If you need to have this done, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose your cruise control problem.

ANSWER : The unfortunate truth is the dealer is correct. What you are doing is in theory feasible but not common at all. I haven’t run across anyone who has done what you are doing and I have often wondered how such an endeavor might work. My point here is, I am not surprised the dealer isn’t sure because it’s likely they have never done this themselves. The dealer doesn’t set up the PCM (Powertrain Control Module) in the cars they sell. The manufacturer does and guessing what happened when a car is being built is not common knowledge.

Anytime you modify any car, there are always details such as this that you will possibly have to address. When you choose to modify a car, you are now the engineer. The simple answer is that I can’t tell you with certainty whether or not the PCM in your car has cruise control capability. The only way to find out is to allow the dealer to check in out. Independent shops might possibly be able to, but the equipment they have is aftermarket and not produced by Mazda. The electronic equipment the dealer has is. The dealer equipment will most likely be able to do what you need.

ANSWER : If you have already replaced the flasher module for the turn signals, your problem may be in the switch assembly whether it is a shorted circuit or the contacts in the switch not making a proper connection and causing problems with other circuits. The problem with the brake lights and cruise control may be the brake light switch on the brake pedal. Consider hiring an experienced technician like one from YourMechanic who can come out and take a closer look at your lighting concerns and offer a more personal diagnosis.

ANSWER : Hi there, thanks for writing in. Usually the P0717 OBD-II error code is associated with a speed sensor problem inside the transmission. This part helps to monitor the cruise control along with the speedometer. If the sensor is damaged or has a loose fitting wire harness, it will disable the cruise control first as a safety measure; but allow the speedometer to work in many cases. The best way to know for sure is to contact one of our mechanics to replace your speed sensor, or inspect the vehicle for cruise control issues.

ANSWER : You will have to have the ABS system scanned and not just the engine computer scanned. You will have to monitor the wheel sensors if you get no codes, but if the light is on there is a code stored in the ABS module. One of the wheel sensors is failing and will cause all the problems you’ve mentioned.

A scanner that can access the ABS of the car is needed for this diagnosis. I’d suggest getting the vehicle looked at by a qualified technician who can properly diagnose your ABS light and repair the issue as necessary.

ANSWER : The problem you are describing likely stems from an intermittent electrical fault in the wiper circuit. The windshield wiper system uses a small electric motor to move the wiper arms that you see on the windshield. That electric motor is controlled through a switch, relay, fuse, and wiring. One, or more, of those electrical components has failed although it is also possible that the mechanical arms are binding (seized, if the lubricant has dried out) thus causing the electric circuit to the motor to overload. Regardless of the underlying fault, if you request a non functioning wiper diagnostic/repair, the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : It seems like the defrost of the vehicle has an issue. There are several possibilities that could cause this. The control unit for the climate control system could be malfunctioning. The fuse for the rear defrost could be blown due to some unknown reason. The windshield itself could be damaged and lost connection somehow. I would recommend having a qualified professional who is proficcient in electrical diagnosis inspect your vehicle with a wiring diagram. This will help to determine where the fault in the defrost system is located. Once the issue is found, I would recommend having the issue resolved as soon as possible to prevent any safety issues that could result from lack of clear vision through the rear window.

ANSWER : Hi there. Most of the time this is cause by a failing brake switch. The switch fails and makes the computer think that you are applying the brakes, which automatically turns the cruise off. This should be checked first. If it is fine then the computer needs to be scanned to see if there is anything else going on. If there are no codes, then it is more than likely the brake switch. If you want to have this repaired, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose the cruise control problem.