D6M trans calibration issue

[r20d12]

SN 3WN1059
Trying to calibrated transmission after rebuild. In certain gears engagement pressure can be set fine. In others the machine will try to move and calibration is stopped by ECM.

It seems to shift fine though. I am going to check for a short in the harness after I post this. I've got 29 years in as a heavy equipment tech. Several of those years as a field guy at Cat dealers and have never had any problems with calibrations.

I realise the ECM is trying to engage a speed and direction clutch at once but it should not be able to do this in calibration mode. Any help would be great.

Thanks!

 

[Nige]

SN 3WN1059
Trying to calibrated transmission after rebuild. In certain gears engagement pressure can be set fine. In others the machine will try to move and calibration is stopped by ECM.

It seems to shift fine though. I am going to check for a short in the harness after I post this. I've got 29 years in as a heavy equipment tech. Several of those years as a field guy at Cat dealers and have never had any problems with calibrations

From what I know you only calibrate one single clutch at a time, so theoretically it should not be possible for the machine to move.
Can you identify a common clutch number that causes the problem to happen..? The wiring for that clutch would be the first port of call for me. Is the solenoid valve for the same clutch getting back-fed from somewhere..?

 

[r20d12]

with J1 and J2 unplugged. I checked for continuity between the "hot" wires for each solenoid. I have around 20 ohms. The manual says no less than 5k... yet, I have no active codes. according to that, the harness is shorted. I disconnected the xmsn harness at the rear of the machine and checked at J1, J2 and have NO continuity. That tells me the xmsn harness is shorted yet... NO CODES

 

[Nige]

Continuity checking without a Diagnostic Code - oh deep joy......

 

[r20d12]

I took good notes. 6 wires including the solenoid return. Compared each wire with the others. Hopefully I'll know more tomorrow. Thanks for responding Nige!