Hey all, I've been working on this 624k for a while now and I can't seem to figure this out. It came to our shop for an engine swap, the old engine blew a head gasket and we replaced the engine and sent the old one to be rebuilt. We also replaced one hyrdaulic cylinder. But after the swap and during testing occasionally after startup the ADU would throw 6 seperate TCU codes about the clutch solenoids. Clutch K3 sol 522392.4 Clutch K4 sol 522389.4 Clutch Fwd sol 522386.4 Clutch Rev sol 522383.4 Clutch K1 sol 522399.4 Clutch K2 sol 522395.4 I've replaced both the TCU and Transmission wiring harness, taken out and recharged both batteries, and cleaned grounds. Has anyone ever seen a similar problem to this? I found minimal information online, and I've read through the manual and tested both the new and old tcu & wiring harness, I'm starting to run around in circles here. If i figure anything out I will update this thread for information.
Welcome to HEF RykerHaun ! Need a serial number please.
DW624KR626959
They are all short to ground codes. To have a short to ground for all the solenoids it has to be the common P78 Red power wire anywhere from the TCU to the solenoids. Have you checked the wiring harness between the TCU and the transmission harness (in the load center)? Checked the harness inside the transmission control valve? Since you replaced the TCU and the transmission harness that leaves you with the harness at the TCU or inside the transmission control valve.
Ive checked the load center harness, its fine. I tested the connector for the harness inside the control valve, it shows everything is fine. My shop won't let me tear it down to look inside, but they want to do a transmission swap, I'm trying to convice them to let us see if we can repair these first. I'll update this thread once we figure out what we are doing. Thanks!
When the transmission works does it work well? It would be a shame to drop in a trans for a wiring issue. You said in your OP that the codes occasionally appeared which leads me to believe that it is intermittent, yes/no? When you "tested" the wires did you perform a thorough "wiggle test" while a meter was connected? Did pull the harness out of place (which may require removal of clamping devices) to visually look for rub points, worn through loom, etc?
WHAT!!??
When it runs it runs fine, and yes it is an intermittent issue. We didn't take the load center harness out of the vehicle but we did follow that p78 wire all the way through and it doesn't have any damage, which leads me to believe that the issue is the internal harness inside the control valve. I didn't mention this before, but I'm in a shop in the Marine Corps in Japan, and we would have to wait a couple months to get the control valve, but we can do a 1-for-1 swap for the entire transmission with another shop that just rebuilds them. Obviously this is a waste but having this ready to operate is higher priority than us waiting for what we actually need to be shipped. Also I am not "authorized" to repair components like that, we are more of parts replacers not mechanics. That's the same reason we replaced the whole engine instead of just replacing the head gasket.
Well, I got in a bit of trouble but I think it was worth it, I went ahead and ignored my staff and took a look inside that control box, and wouldn't you know it everything was fine. All solenoids had 19 ohms between themselves, nothing was shorting and no damage on the harness. Every wire has continuity and with the help of some local Japanese contractors we removed and tested that load center harness and it's fine too, we also looked if the way it was routed it might be rubbing against something or getting damaged but all was fine. We definitely aren't doing a tranny swap anymore thank god, but we're still scratching our heads on this. I think something we did when we replaced that engine is the issue, maybe a bad ground? Anyways I want to thank you all for helping me out here, I'd probably get in a world of **** if I swapped a $28k transmission for no reason
Check the grounds at the starter. That is where the TCU is grounded (G22 Black wire).
Good advice, but earlier today we got everything back installed, operated it more, still throwing the codes. We got some new batteries delivered for a different tractor in, but the mech working on that one mixed up which tractor he was working on and installed them in this one. And the codes haven't come back since. We started up repeatedly, trying to do everything to get the codes to come back, but they aren't. I'm still not sure why new batteries fixed it. We load tested the batteries when we first started and they weren't in great shape but they still had plenty of life, one had 1300CCA and one had 1050CCA. I'm relieved we can get this gear back to it's owning unit but I'm still confused on why it's fixed. Thank you again for all the help you've given me!