Recently purchased a CAT 2015 953D track loader. I’m getting several error codes 2687-8 Rt Drive Motor Spd Snr #1 Abnormal Signal Frequency 2686-8 Lt Drive Motor Spd Snr #2 Abnormal Signal Frequency Do you think I need to replace both sensor and if so is it common to both go out at the same time? How hard are they to replace?
Pics of codes
I think I would look at wiring harness. Strange to have right and left sensors both bad
One sensor out of two on each side to be bad is certainly unusual. To check wiring you really need an electrical schematic but there is a small problem. There are no less than six different versions depending on the machine Serial Number (LBPxxxxx), so it might be an idea to start with that. Meantime here are the troubleshooting procedures for the 2686-8 & 2687-8 you have, although in truth you really need the full electrical schematic as well because it shows harness connector locations.