ABS problems


scotts96gt
10-26-2011, 07:43 PM
Anyone have any good ways to start trouble shooting the ABS system on a 99 century. I have a problem somewhere with the passenger side front sensor and or related wiring. Replaced the Hub/sensor assembly and the light went off for 5 mins but came back on. Not sure where to start and what to even look for. I am under the assumption i have a bad connection or broken or loose wires. There is also the possibility i have a bad sensor again as well but not sure how to do a down and dirty test on it. I dont have an ABS scanner and our local shop is a PITA to get in and have it scanned

Tech II
10-26-2011, 08:41 PM
How did you know the LF circuit was the problem?

Let's assume you had a code for the LF wheel....Without a scan tool, it's just a guess....usually the sensor(part of the hub), or the wire harness to it....If you initially disconnected the harness from the sensor, and water came out of the connection, could have a water intrusion problem, which requires the hub/sensor AND the wire harness to be replaced....

What a tech would do, is put the car on a lift and look at data from the LF wheel with a scan tool, if he rotates the wheel, and gets no data, he disconnects the sensor and attaches the new hub to the harness...he rotates the hub, and if he now gets data , he knows it's the sensor....

If he gets no data still, 99% of the time it's the harness(very rare it's the EBCM)....a resistance check to the EBCM would verify it, but it's rarely needed to be done....

However, just one time, I ran into a case where a wire harness loom, rubbed against the A/C accumulator, and caused this problem.....there was a TSB out on this....caused various problems, depending on which wire/circuit was affected......FYI...

scotts96gt
10-28-2011, 05:46 AM
The shop that had done some work to the car scanned it for me (which is also when the ABS light cane on) and said that the sensor was coming up bad. I already replaced the hub/sensor assembly, the light went off for a short period of time and now is back on.

gmtech1
10-28-2011, 07:47 AM
Sounds to me like the harness is broken down at the control arm. You can pull the wires out of the loom about 8" or so back from the connector to the sensor and inspect them. Most of the time the wire strands break inside the insulation and you cannot see it. The jumper harness runs about 75.00.

scotts96gt
02-23-2012, 08:26 PM
Does anyone know what the part numbers are for the ABS connectors on a 99 century? both the car side and the speed sensor side? or better yet the part number for the jumper harness. All the searching i have done it seems like the low coolant sensor connector is the one that can be used on the car side but the bad connection i have is at the hub itself in the jumper connector

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