ABS Help - Low Speed ABS Engagement

[jlisk]

Hello, I am new to this thread so I apologize if this is in the wrong section. I have a 99 Ranger, XLT, 4x4 with 88k miles. Recently the ABS light came on, so I hooked up the OBD-II reader and found that the rear speed sensor (in the rear diff) was bad. I went ahead an purchased a new sensor and replaced the old, as well as cleared the bad sensor code from the ECU. After I put the new sensor in I took the truck for a test drive, and notice that the ABS engages when I slow down, at about 5mph.

I've heard of some people having this low-speed ABS engagement due to front sensors going bad, however my ABS was not doing this before I replaced the rear speed sensor. I checked the resistance on my front to sensors and found that they were both in the 0.420-0.425 k Ohm range with the hub stationary (not rotating).

Does anybody have any suggestions or past experiences with this issue? I am really hesistant to try replacing both front sensors due to the high price; could the new rear sensor I have possibly be out of spec and that be the cause? I haven't tested the rear sensor resistance yet, but can try if anybody knows the range it should be in.

Thank you in advance, I appreciate the support!

 

[hondaxr650]

Are you 100% sure the rear sensor is in all the way? If it isn't seated all the way into the housing , you could have excessive gap between the sensor and tone ring, causing it to lose the signal.
BTW the resistance spec for the rear sensor is .8-3.5 kilo-ohms.

 

[jlisk]

I'm 99% sure the sensor is fully seated, as I spent some time to make sure it was in properly. However I will double check this evening to get to that 100%. Thank you for the resistance spec as well, I will test to see if it is within specification. If the rear sensor is in fact seated properly, and the new rear sensor is within spec, are there any other causes of this malfunction, or ways to see if i really do need new front sensors?