ABS/TCS woes, BCM or EBCM? What else??
01-09-2019, 03:42 PM
#1
ABS/TCS woes, BCM or EBCM? What else?? Got and issue with the ABS/TCS/BRAKE lights always being on and I'm running out of ideas. It is a 4-channel car. This is my WIFE's car and I want to fix this for her and her safety.
I have tried to scan the ABS codes, but I get a "cannot communicate error"
So far I have:
Checked all fuses
Replaced burned out 3rd brake light bulb
Cleaned grounds related to ABS Block(EBCM)
Replaced EBCM with known good 4 channel EBCM
Cleaned connections to ABS sensors front and rear
Cleaned reluctor wheels and sensors on rear axle
Where do I go from here? Does the BCM under the dash have anything to do with the ABS/TCS? Help would be greatly appreciated.
Jon
I have tried to scan the ABS codes, but I get a "cannot communicate error"
So far I have:
Checked all fuses
Replaced burned out 3rd brake light bulb
Cleaned grounds related to ABS Block(EBCM)
Replaced EBCM with known good 4 channel EBCM
Cleaned connections to ABS sensors front and rear
Cleaned reluctor wheels and sensors on rear axle
Where do I go from here? Does the BCM under the dash have anything to do with the ABS/TCS? Help would be greatly appreciated.
Jon
01-09-2019, 06:47 PM
#2
How many miles? Replaced front hubs? Not sure if they can "go bad" as far as ABS, but when racing I have gotten ABS issues from really taxing the car. But mine usually cleared up after turning it off and later starting it up again. Just a thought.
01-09-2019, 08:41 PM
#4
by no means am i mechanic, but anytime i have had an abs issue with these cars (twice) both times i was able to learn a lot by getting live data from the wheel speed sensors.
the first i went to my small town chevy dealer who plugged in the tech 2 and just drove around........
the second time my small town shop who i get favors from from time to time (no idea why he is so nice) hooked up his generic garage tablet to it, and we drove watching the sensors. i saw that periodically all my wheels read 0 for a split second. i did have 2 codes tho and basically knew that i checked the grounds, and that it had to be a bad module. replaced module, issue fixed.
seeing if they are reading at all will get you started since you dont have codes, but i would say if your sensors areent saying anything you definitely have a wire issue somewhere. last i looked at a wiring diagram for the 4 channel basically all wires go solely to abs related components or the fuse box....then a few to the dash for warning lights. i do believe 1 goes to the pcm but that is just to tell the PCM to pull timing in a wheel slip.
the first i went to my small town chevy dealer who plugged in the tech 2 and just drove around........
the second time my small town shop who i get favors from from time to time (no idea why he is so nice) hooked up his generic garage tablet to it, and we drove watching the sensors. i saw that periodically all my wheels read 0 for a split second. i did have 2 codes tho and basically knew that i checked the grounds, and that it had to be a bad module. replaced module, issue fixed.
seeing if they are reading at all will get you started since you dont have codes, but i would say if your sensors areent saying anything you definitely have a wire issue somewhere. last i looked at a wiring diagram for the 4 channel basically all wires go solely to abs related components or the fuse box....then a few to the dash for warning lights. i do believe 1 goes to the pcm but that is just to tell the PCM to pull timing in a wheel slip.
01-09-2019, 08:50 PM
#5
by no means am i mechanic, but anytime i have had an abs issue with these cars (twice) both times i was able to learn a lot by getting live data from the wheel speed sensors.
the first i went to my small town chevy dealer who plugged in the tech 2 and just drove around........
the second time my small town shop who i get favors from from time to time (no idea why he is so nice) hooked up his generic garage tablet to it, and we drove watching the sensors. i saw that periodically all my wheels read 0 for a split second. i did have 2 codes tho and basically knew that i checked the grounds, and that it had to be a bad module. replaced module, issue fixed.
seeing if they are reading at all will get you started since you dont have codes, but i would say if your sensors areent saying anything you definitely have a wire issue somewhere. last i looked at a wiring diagram for the 4 channel basically all wires go solely to abs related components or the fuse box....then a few to the dash for warning lights. i do believe 1 goes to the pcm but that is just to tell the PCM to pull timing in a wheel slip.
the first i went to my small town chevy dealer who plugged in the tech 2 and just drove around........
the second time my small town shop who i get favors from from time to time (no idea why he is so nice) hooked up his generic garage tablet to it, and we drove watching the sensors. i saw that periodically all my wheels read 0 for a split second. i did have 2 codes tho and basically knew that i checked the grounds, and that it had to be a bad module. replaced module, issue fixed.
seeing if they are reading at all will get you started since you dont have codes, but i would say if your sensors areent saying anything you definitely have a wire issue somewhere. last i looked at a wiring diagram for the 4 channel basically all wires go solely to abs related components or the fuse box....then a few to the dash for warning lights. i do believe 1 goes to the pcm but that is just to tell the PCM to pull timing in a wheel slip.
It's not that I don't have codes, my ABS scanner simply cannot establish a connection with the ebcm.
01-09-2019, 09:15 PM
#6
I've got plenty of personal and professional experience, and I think I have done everything except tracing individual wires. I'm asking to make sure I'm not missing something stupid and also if there was a common fix for the "no communication" error.
It's not that I don't have codes, my ABS scanner simply cannot establish a connection with the ebcm.
It's not that I don't have codes, my ABS scanner simply cannot establish a connection with the ebcm.
01-09-2019, 09:17 PM
#7
basically i was going with, if you could see that your wheel speed sensors arent working, then you know you have a huge issue with the EBCM, which you already replaced telling us if that module u replaced it with was known as good, then you have a car issue.
