Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Hello, my name is Bobby. Thank you for the question. Can you tell me if the truck is all stock? How many miles are on it?
Thank you. Most of the time if this hesitation happens when it is cold it is due to a failure in the coolant temperature sensor or a failing air flow sensor. Both of these are common and will cause this on your vehicle. As for the brakes, it sounds like the ABS is kicking in at this low speed. Most of the time this is caused by a failing front wheel speed sensor. If you have an odd tire size on the front or if all of the tires on the truck do not match then this will occur. If the tires are fine then it is more than likely a bad sensor.
Unfortunately the only test you can do that is a real true test would be with a computer scan tool that reads this engine and ABS data. You would need to monitor the wheel speed signals as well as the coolant temperature and the air flow reading. If you do not have one with this capability then you can do a voltage test of the front speed sensors, but it will only allow you to see an initial voltage reading.
It does not have a specific scan tool, just one that communicates with all of the modules and shows you the sensor signals.
Typically these two sensors will read incorrectly and it will not cause a check engine light. Low fuel pressure would not cause a check engine light also.
Does the scan tool read engine data or just codes?
No problem. Let me know when you get a chance. If I am not online when you return give me some time to respond. Thank you and have a great night.
If you cannot see this information it will be hard to diagnose. If it cannot ID it then it cannot communicate with it. You might want to try another scanner. Most auto parts stores will scan computers for free and give you the codes.
I would remove the air flow sensor and clean it. Using mass air flow sensor spray cleaner you can spray it out. I would also replace the coolant sensor as that is fairly inexpensive.
It depends on if it is the scan tool or the PCM. If it is the PCM then it may be failing or you may have a bad fuse. I would check the fuses in the fuse box under the hood. Pay close attention to the lighter fuse.
They are called the wheel speed sensors. I hate to see you just replace parts without knowing for sure that they are bad
Check your fuses first to see if we can get the PCM to communicate with your scanner first. If we can communicate with the PCM we can get some answers.
Thank you Jack. Please let me know.
Let me know what happens when you replace them and we can continue as needed.
How old are the rear brakes ? Have they been adjusted recently?