My Cat 276B auxiliary hydraulics are not working. What could be the problem? CAT0277BHMDH02971

Hello

Thank you for using JustAnswer. My name is*****'d like to try and help. I am sorry that you are having issues. I know this can be frustrating. I'm a technician of all kind of industrial equipment and I will try to help you today.

Do you have the optional right hand display console?
Just be aware The auxiliary ECM has been known to fail on these machines however there are a few simple tests you can do to try and isolate the problem.
1/ lift the cab hook a LED test light across one of the aux solenoid coils with enough lead to reach the in to the cab with the back in its lowered position operate the machine and check the status of the test light if it comes on while operating the machine yo may have an hydraulic problem
2/ gain access to the 12 in connector for the RH joystick and check that you have power between pin 1 (8 vdc) and pin 2 ground return. if no power you need to check that the ECM battery voltage between pins 1 and 3 at the ECM.if no power at the ECM you have a possible harness problem which will need to be addressed.
3 /If all this is ok, next check that you have a signal coming out of pin 3 at the 12 pin connector (check with multimeter set on duty cycle setting and connected to pins 2 and 3) while moving the joystick you should have a varying duty cycle reading.
4/ if that is ok you need to check the duty cycle output from the ECM between pins 42 and 58 and 42 and 40 .
5/ if ok check the duty cycle at the control valve aux solenoid coils using extension test leads that will reach in to the cab
6 if this is ok check the resistance of the control valve aux solenoid coils
if there is no output at the ECM and you are positive that you have good power and good earths there iis only one thing lef to do before condemning the ECM and that is to try to reflash the ECM unfortunately unless you have a dealer version of ET you cant do it your self

Thanks for the update.

Follow the instruction i sent and lets see what you have