Hi. I have a 05 cat 277b. It is stuck in park on my trailer. Both lights flash. The parking light and the arm rest indicator. I tested all the solenoids and they are good. I pulled up the plate under the foot pedal and removed the harness from the ecm. I checked contact wires 3 to contact wires 68. (201-BK and wire 975-WH) and it says it should be greater than 5000 ohms. I just get OL. I am thinking one of those is a dead wire. I have a schematic in from of me but am trying to figure out where it leads to so I can check else where. Any tips? Thanks
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Cat 277b stuck in park
- Thread starter Iggys6
- Start date
Nige
Senior Member
What schematic do you have..? A genuine Cat one or a "will fit"..? A Cat schematic should leave you in no doubt as to where each wire goes.
To get the correct schematic a Serial Number would be nice.
To get the correct schematic a Serial Number would be nice.
Hi, I am looking at this schematic, the last page. Says volume 2 of 2. The serial number is CAT0277BEMDH02115
Mark250
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5000 ohms or greater is CATs way of saying no connection between contact 3 and 68 which is the battery negative to the common return wire.
O/L in multimeter lingo means open circuit
Yea that is what I'm looking at. Where does the contact 3 lead so I can check for a open in that wire and then I could check for a open in the ground wire (contact 68)
Nige
Senior Member
If you look at the interlock ECM on Page 2 of the schematic all the wires that come out of it appear to go into a thick vertical black line, including 201-BK & 975-WH. That line indicates a common harness. If you follow that line downwards a tad you will see a slightly thinner horizontal black line, again a common harness. That goes into another thick vertical line, etc, etc, until it finally ends up at a 12-pin connector (Grid ref G-3 on Page 2 of the schematic) marked "CONN 8". There is a note next to the connector that gives 2 alternate locations on Sheet 1 schematic where the other side of CONN 8 will be located. In the "Attachment & Cab Connector Locations" table located on Page 3 of 4 there is a key that details the machine location for each connector. According to that CONN 8 is located at #34 which appears to be somewhere behind the operator's seat.
Hope that helps.............
Hope that helps.............
Mark250
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contact #3(black) is a ground wire that goes to the ground stud on bottom plate
contact #68 is a common wire the is connected to the transmission solenoid, the detent solenoid and the work tool pilot solenoid
sounds like you have access to the trouble shooting guide have you followed the steps in that publication
Mark
Ok I couldn't really trace the wiring as it was a little dirty so I disconnected the battery and washed it all down. I still get OL when I probe #3 and #68. When I probe #3 and then probe something metal like a bolt I get 1.5-3.5 ohms so I'm figuring the ground is good. So I put the connector back on the ecm just to see if it's still flashing and now when you turn the key on the parking light lights up and goes right off. it doesn't flash or stay on like it should. I sure hope I didn't cause damage to the ecm from washing it. 
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Mark250
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hi, OL is the correct response when you probe #3 and #68 its just saying that the wire #68 is not groundedOk I couldn't really trace the wiring as it was a little dirty so I disconnected the battery and washed it all down. I still get OL when I probe #3 and #68. When I probe #3 and then probe something metal like a bolt I get 1.5-3.5 ohms so I'm figuring the ground is good. So I put the connector back on the ecm just to see if it's still flashing and now when you turn the key on the parking light lights up and goes right off. it doesn't flash or stay on like it should. I sure hope I didn't cause damage to the ecm from washing it.
1.5-3.5 is also the correct response for wire#3 to ground because it is the ground wire
if you have water in connectors unplug and blow out use a hair dryer if you have to or allow time
so if ol is the correct reading to get then what do you think is wrong.. a solenoid? the aux hydralics work, there just is no parking light on now at all when it used to flash as well as the arm rest bar flashed. now i get nothing
Mark250
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have you followed the troubleshooting guide? you have followed the first step there are a number of other steps that check different parts of the circuit
No I stopped following the troubleshooting guide because I kept getting ol so I thought I had a open in the wire. but if I'm supposed to get OL then I will continue to follow that guide. I'm just pretty confused now because I get no flashing lights or solid lights at all now after washing it
Ok so I began to follow the troubleshooting guide and I'm on Step 6, Check the circuit for the hydrostatic pilot solenoid for a short to the + battery terminal.
Measure the resistance at the wire harness connector from pin 29 to the following pins, 1, 11, 13, 24, 42, 47, 58, 60, 62, and 70. resistance should be greater than 5k ohms. I believe this is the problem the only pin I have that is getting resistance is pin 24. and about 2 ohms. I am looking for chaffing wires and I do not see anything. Hopefully one of you guys know better than I do.
Mark250
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well done, good find a couple of options from here
1/replace the loom expensive and time consuming
2/spend some time and look /feel for the damaged harness area
3/bypass wire #29 and run a separate wire from the ECM to the left hand joystick xmsn solenoid
preferred option would be option #1 but if it was mine I would spend some time on option #2 or #3
1/replace the loom expensive and time consuming
2/spend some time and look /feel for the damaged harness area
3/bypass wire #29 and run a separate wire from the ECM to the left hand joystick xmsn solenoid
preferred option would be option #1 but if it was mine I would spend some time on option #2 or #3
Thank you for all the help. I will try option 2 right now but worse comes worse I will do option 3 as I desperately need it for tomorrow. Where does wire #29 go to? I'm trying to look at the schematic but I only have a few years experience so some guidance would be greatly appreciated.
Mark250
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wire #H416 green goes from pin #29 on the ECM to the left hand joystick .the solenoid has a two pin connector .pin # 1 is the other end of H416
Mark
Mark
Ok thanks I'm looking now but of course the wires are loomed in something impossible to look through rather then just wire loom. So It's just a straight wire from pin 29 right up to the solenoid? it doesn't go through the fuse box or anything? Thanks
I just probed pin 29 and the green wire on the left joystick solenoid connector and got 000.0 which means that the green wire is good.