I am working on A Cat D250E Articulated truck PIN#5TN01600 Transmission # 5EX02579. . I am having problems with the automatic transmission. When i put it in drive it will only stay in low gear no matter what gear i put it in. When in reverse it will work in reverse high and reverse low. When we bypassed the electrical system and moved the gears manually all gears work. We took the ECM for the transmission to a shop to get it looked at they said it was working properly. I am also getting 24V at up solenoid. The lock up solenoid and down solenoid read 4.6V. Thanks for helping. The ECM for the transmission has a display screen that shows logged codes: 602-F03 681-F03 681-F04 700-F02 700-F07 702-F02 707-F03 707-F05 707-F06 * 708-F05 * 709-F03 709-F05 We also did not test the TOS. What are ways I can test it with a DMM? Also in the the cab the Transmission warning lamp is on.
Hi Charles, you have some heavy duty faults logged there 602-p2 pressure sensor 681-park brake/solenoid driver 700-trans gear switch 702-shift lever switch 707-upshift solenoid 708-down shift solenoid 709-lock up solenoid 1/ I would be checking common points ie power circuits and earth points 2/ do you know how to check if the codes displayed are active or logged? if not we can help 3/looking at the list as stated fault 681-03 and 681-04 will give the symptoms you have described ,a faulty park brake circuit or the park brake solenoid driver circuit could give you your problem 4/ do you have access to schematics and testing info ? we can help there also Regards Mark
I have cleared all the codes and no new codes pop up. TOS in drive shows 26. Transmission oil temperature light stays on even in early morning start up. Transmission still does not shift.
hi check the body float indicator light on the ECM. looking at the display it is the top right hand corner and should be on, other wise gear limit is first (factory setting) Mark
hi, the light is operated by a temperature switch (two terminal switch mounted in oil cooler flange if it has a retarder) to check the trans/retarder indicator light ground the wire #407(pink) and the indicator should go out in the EMS panel if not it means you have an open circuit between the switch and the EMS panel(or bad panel, unlikely)
My vote would be for the ECM getting a body up signal from somewhere and thus limiting the transmission to 1st gear. It's very rare in my experience for any owner to change the body up gear limit from the standard factory setting.
Hi Charles, I know your thread is old, just wondering what you ended up doing to get your truck working. Im currently working on a Cat D300E and am having troubles with shifting. It works in 1st and Reverse High. Every once in a while I can get it to shift up but its intermitent. Thanks
With symptoms like you describe I would suspect a speed sensor or speed sensor wiring fault. Typically a loss of speed sensor signal will prevent the transmission shifting beyond 1st speed. EDITA: If you want an electrical schematic then post a Serial Number.
Hello Nige, My TOS reads 18 with about 2200 engine RPM. Intermitently it will begin to shift for me. Usually after I go from reverse to drive a couple times. I have the testing and service manuals and am currently testing. Thank You
I suggest to try removing the TOS and inspect the head for damage/particles/debris. It will also be a good opportunity to re-adjust it when you put it back in.
Hi Nige, So I pulled the TOS. It looked good. I found some small metal filings on it, and some small filings on the clutch lock up solenoid/cartridge. Possibly a sign of worse things to come. Going to do some pressure testing tommorow. Is it common to have a ETCM go out on these? I did some test driving with a multimeter hooked to the upshift solenoid and the ETCM set to mode 7 to watch the TOS. It would shift to 3rd gear but no further. The TOS was reading RPM's that should have called for an up shift but the voltage wasnt there. Thanks
Did you readjust the TOS when you reinstalled it.? Those old-style electronic controls were relatively bullet-proof. It's always possible for one to fail i guess but based on your symptoms I would say the most likely cause is wiring. Let's face it, the signal from the control for an upshift is the same signal whether it's a 1-2 or a 5-6 upshift, it simply sends an electrical supply to energize the upshift solenoid. So if the transmission upshifted as far as 3rd then electronically the control ought to be OK. Here's a thought. Have you checked the operation of the torque converter lockup clutch.? If that isn't fully engaging you can be a little shy on the necessary ground speed for getting upshifts. If you have suitable terrain available try operating the truck downhill and see if it upshifts. if it does then my money is on the lockup clutch.
this thread is helpful but haven't solve my problem yet. please I'm working on D300E now. the problem is it can not move. no gear is engaging but from the monitor i can read out any gear position i shift the gear lever to but machine not moving. the owner said the problem happens when water covered the truck from night to morning. they were using it to carry sand from river and they left it there not knowing the river would over flow the night. we have done flushing the complete system and put new oil but still it won't move. please any help that can help making it move again will be so appreciated. thanks.