2ZK06764 Just had machine in shop for new radiator, rad hoses, heater hoses and a full transmission service (spotless screens/filter) Worked a full day after that with no issues Tried to take it to a job a few days later and no high range (5678F) / (456R) Have had this happen before with low range so figured it would just be a shift solenoid gone again ET gave me 4 (logged) codes None active 644- 3 Transmission Solenoid 4: Voltage Above Normal 644-5 Transmission Solenoid 4: Current Below Normal 644-6 Transmission Solenoid 4: Current Above Normal 168-1 Electrical System Voltage: Low Changed solenoid #4 out with a full new assembly and still no go Machine won’t throw any more codes to lead me in one direction or another I have seen on this forum that transmission ECMs can cause grief as well as shifter assemblies Hoping someone can lead me in the right direction with no codes as clues Thanks in advance
Don't recall seeing that. Highly unlikely, although possible. Clutch #4 isn't high range unless you are using a different numbering method to the one to my charts. #8 is high range. It's also engaged in both Neutral and Park which is a good check.
Nige, this is the photo that i was going off of from my manual solenoid (D) is the one i changed
OK, so different illustrations. It's called a "Cat design feature" Try testing whether solenoid valve "D" is energized with the transmission in both Neutral and Park. If it is then hook a pressure gauge up to the test point and just make sure the clutch is getting pressurized.
Will update on solenoid voltage tomorrow. so far all I’ve determined is it’s time for new battery’s as every time I go out to test something the battery charger has to be involved to get machine fired up Also found one wire hanging on by a thread E946 OR MG MESH CNTL - Forward Direct Unsure if that has potential to be the culprit
If it is one of the wires feeding the high range clutch then there is a distinct possibility. What does the schematic indicate.? I can’t look at it at the moment. EDIT: I just took a look at the schematic (I assume you are using SENR9147) and E946 is a wire between the transmission Spd/Dir switch and the powertrain ECM makred "Forward". So IMO it should affect all forward speeds but TBH until you fix the damage you found you won't know one way or the other. Another thing is that the transmission wiring harness (the short one mounted on the control valve itself) usually cooks on machines with high operating hours and the insulation becomes brittle leading to internal wire failures. If yours is like that I would suggest a replacement. It's shown as #8 on the attachment.
Repaired wire break no luck Testing in park I have good power to solenoid (G) Meter reading around 1.1V to (D) Will start testing harnesses back to ecm
In park you should also have power on solenoid H (#8) on your diagram. Did you also check that.? I know it’s got nothing to do with high range but you need info regarding whether the correct solenoids are being powered up at the right time.
Tested both G and D good power on G but little to none on D H is functioning correctly
If it’s a consistent fault my first thought would be the harness(es) until proved otherwise. If it was the transmission control on the fritz you would think it would set one or more Active Codes
Harness continuity tested fine Traced wires for solenoid D back to the transmission controller and tested voltage there Only just over 1V coming from controller plug I agree on the more active codes thought. Really not giving me much to work with Was at cat dealer today and it’s a good thing I was sitting down when they told me the price of an transmission controller these days
Try it with a 5A test light rather than a simple resistance test. Sometimes a wire can be hanging on by a thread and show continuity with a multimeter but when you ask it to pass significant current it will fail. If you did that by back probing try it with the harness disconnected from the controller. There might be something somewhere pulling the voltage down.
Update to finish this post out After a lot of harness testing (thank you Nige for all the help) everything checked out. I ended up tracking down a used transmission controller for testing purposes and now machine is back in action. Will be sending original TCM out in hopes to have it repaired
Considering the cost of a replacement it’s always worth going the extra mile when troubleshooting before declaring an ECM officially dead.