My ABS light is on most of the time. When I first start the engine it will be on, but when I put the truck in gear, either forward or reverse, it will shut of after moving only 5 or 10 feet. It will stay off for 2 or 3 blocks before it will come back on and stay on until you shut it off and start the process over again. I have replaced the left front ABS sensor and the right front hub an bearing assembly, which has a new ABS sensor in it already. A scanner still says the both front ABS sensors are at fault. I have unhooked the sensors and the ABS motor and unhooked the battery and nothing has changed. All connections look very clean and the pins look straight. Any suggestions?
I don’t have a lot of experience with ABS systems. But I do know that you want to know what the exact and specific error codes are and then what exact and specific conditions set those codes. A car’s computer(s) never has direct access to a sensor’s condition. At the very least it is dependent on the wires in between. You have checked your connector pins. So what about the rest of the circuit, for instance? There are multiple error codes that may occur for these sensors. They will probably all refer to CIRCUITS - not sensors.
In the case of speed sensing, it is also the case that the computer generally has to use comparisons of readings among different sensors. It has no direct “knowledge” of vehicle speed - it just has to get that from sensors. Whatever your error codes are they might just refer to something like a correlation/inconsistency between speed readings from different sensors. But that’s why you need to find out in exact and precise terms what actually triggers the codes you are getting.
How are your front tires? Do they match and have reasonably god tread?
I would think the wiring is OK since the light does go out when I first move the truck. I also hooked up a scanner to it and drove the vehicle a couple of miles and the MPH from both front sensors was very close to the odometer reading. When I pulled the truck into the garage to hook up the scanner, the light had gone out, so the scanner listed the codes as “History”. Two of the codes were for the front two sensors. One code was “Device voltage low”, one was right front ABS channel in release too long, and that sensor was replaced with a new hub and bearing assembly, and the last code was for a class 2 data link.
Does this mean anything to anyone?+
My front tires are about 40% tread and aired up properly.