Error Code P0574 is defined as Cruise Control System – Vehicle Speed Too High, this means the vehicle is traveling too fast for the cruise control system to set.
This code is a generic trouble code that typically applies to vehicles equipped with the OBD-II with cruise control. This includes vehicles from but not limited to Audi, Chevrolet, Citroen, Ford, Hyundai, Nissan, Peugeot, and Volkswagen. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model, year, and powertrain configuration to another.
Many functions come with the vehicle’s cruise control feature. Drivers can set a specific vehicle speed, and the vehicle will maintain it automatically using numerous sensors, modules, switches, etc. Drivers can also modify (i.e. “set – “ & “resume +”) temporarily modify speed while storing previous speed (i.e., unexpected stopping/slowing, passing vehicles), etc.
When this code appears, that means the PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes) has detected a malfunction(s) within the signal circuit. When the PCM detects a signal malfunction within one or more of the many functions of the cruise control, it activates the Check Engine Light and registers the code. This will also mean the said function will be disabled or act abnormally.
In this particular error code, the PCM has determined that that vehicle is traveling too fast from the allowable speed for the cruise control system.
When driving using the cruise control function, the PCM works alongside with the cruise control module to make sure the vehicle is traveling at the same speed. If the PCM detects any abnormality, such as vehicle exceeding allowable speed limit, the cruise control system will run a self-test for its entire system to try to look for the source of the problem.
Other related cruise control codes include:
- Error Code P0575
- Error Code P0576
- Error Code P0577
- Error Code P0578
- Error Code P0579
- Error Code P0580
- Error Code P0581
- Error Code P0582
- Error Code P0583
- Error Code P0584
- Error Code P0585
- Error Code P0586
- Error Code P0587
- Error Code P0588
- Error Code P0589
- Error Code P0590
- Error Code P0591
- Error Code P0592
- Error Code P0593
- Error Code P0594
- Error Code P0595
As said earlier, this code activates the Check Engine light and registers the code to the vehicle’s memory system. Other common symptoms include:
- Erratic or intermittent cruise control function(s) operation
- Cruise control light is on or does not come on
- Faulty cruise control switch is the most common cause for abnormal voltage or resistance level, which could be caused by spilled liquids that shorts circuits the device and circuits within.
- Defective wiring (short to ground, open circuit, short to power, etc.)
- Open or shorted cruise control function switch(s)
- Internal short or open on PCM
- Damaged connectors within the cruise control system
- Blown fuses (could indicate a more serious problem, such as short, defective control module(s), and voltage spikes.)
How to Check
The first thing you should do is check all the connectors, components, and wirings for any damages
Then, download the freeze frame data and stored codes in case of intermittent code issue, before clearing the code and retesting the system.
If the code comes back, that’s a sign of defective cruise control switch.
If possible, raise the vehicle and with the help of an assistant, allow the speedometer to reach around 25 to 35 MPH. Then set the cruise control. This will let you test the continuity of the cruise control circuits while the vehicle and cruise control system are running.
Then, disconnect the electrical connector from the cruise control switch and test it for voltage using the digital volt/ohm meter (DVOM). Compare your findings to the specifications set by the manufacturer.
If there is neither voltage or ground signal at cruise control switch, you should disconnect the PCM from the cruise control module, and check for continuity of the circuits between the switches in the passenger compartment, fuse panel, and PCM. Again, compare findings with the manufacturer’s specs.
Next, test voltage of the cruise control On/Off switch using the DVOM.
Make sure you clear the code and retest the system to see if it returns.
How to Fix
Common repairs for this code include:
- Replacement of faulty wiring, connectors, or components, especially corroded, shorted, or otherwise damaged
- Replacement of faulty cruise control switches
- Replacement of blown fuses. This should be determined by a qualified mechanic.
- Replacement of faulty cruise control On/Off switch
When this code appears, then the cruise control will not be set. If this function is important for you, then you should have this problem addressed as soon as possible.
The most common mistake in addressing this issue is overlooking the blown fuses and making unnecessary replacements.