I searched the forums but failed to find a solution. I have a Caterpillar D6R XL 5LN problem. The machine runs fine for a short bit but then the brakes engage. If you keep the machine under 1350 rpms it works fine. The brakes engage if you go higher than that. According to the error code, it says the #2 speed sensor is faulty. However, I have: Changed all the speed sensors; Had the transmission rebuilt to solve what the technicians said was an internal leak in the transmission; Ohm tested the primary wiring harness that connects the ECM to the speed sensors; Had the ECM tested (it was good) My next task is to Ohm test the connections in the transmission from the plug to the speed sensors. Anyone have any thoughts? Thank you, Russell
What Code did you have that indicated that the #2 speed sensor was faulty.? Did you perform the troubleshooting procedure applicable to the Code or did you simply change the sensor.? The possibility exists that you have a wiring problem rather than a sensor problem.
Thanks for the reply. The code is 13 0673.02. I just changed the sensor.
Bad wire or misadjusted speed sensor if it is in fact adjustable.
I think these have about 4 internal speed sensors which should all be changed as part of a transmission rebuild. They are very hard to get to with transmission installed. Where was the sensor you changed?
You need to ohm test AND load test the wires.
Sorry I tought I posted this morning, but it didn't upload for some reason. Try the attached troubleshooting procedure and see where it takes you. The harness inside the transmission is a common failure mode.
You may also look at the transmission temp sensor. The brakes will drag and give you shifting problems when it has problems. at does have a update where they did away with the 4 speed sensors and only use 2 in the transmission. Was yours updated when the transmission was replaced?