Cat IT24F transmission

Cat IT24F, Serial 4NN00845, Hours 16416, Engine 3114, Transmission 6YX04002. Problem Powertrain not working, drained oil, very dark, filter looks very old, no smell, some material in screen, some fillings on magnet, Used a 4C-8195 control service tool, and got code 74, CID-FMI 650-02, “the harness code is invalid”. Checked Pressures, at filter low idle 70 psi, high idle 300 psi, port B 22 psi, C 0 psi, D 35 psi. Checked solenoids with screwdriver none working, trouble started with loosing 2nd gear forward, then 2nd gear reverse, then lost them all, Somebody worked on this before me, and did retrieve codes, replaced 2 solenoid assembles, they must have cleared the codes, , information from them can not be obtained. There is no input voltage to the shift control lever, I realize that the transmission has to come out, but I would like to know why I have no shift control?

Attached the troubleshooting procedure for 650-02. Sorry but the illustration does not want to reproduce. I'll send you an electrical schematic. Keep an eye on your message inbox. I would suggest to go for the electrical side first. It may be the transmission doesn't need to come out after all.

Thanks Nige, I checked for continuity, there is NOT continuity, could the code be there because the shift lever has failed? or from disconnecting and reconnecting wiring?

wrightdj said: I checked for continuity, Click to expand... Where exactly.? What you really need to do is to use the electrical schematic and check the continuity of the Harness Code plug (CONN 13). You should have continuity between Pins 1, 2, 3, 4, & 7. Pins 5, 6, & 8 should be open circuit. If the Harness Code plug connections test good then individually check the continuity of the 5 wires between CONN 13 and the transmission control, plus the black wire from Pin 2 of CONN 13 to machine frame ground.

Code 650-02 I tested at the ECM behind the seat, was NO continuity. This connection 13 is the diagnostic plug? here I only have continuity between 2 and 1,3,4,and 7, and only when + is on 2, no continuity any other way.

wrightdj said: This connection 13 is the diagnostic plug? Click to expand... No. It’s the Harness Code connector. Can you not see it on the schematic.? Located in Grid E-10 on Page 2 of the electrical schematic I sent to you.

Nige said: No. It’s the Harness Code connector. Can you not see it on the schematic.? Located in Grid E-10 on Page 2 of the electrical schematic I sent to you. Click to expand... Yes, I checked the wire #s, this is conn 13,

OK, so two questions.

1. Do you have the correct continuity on the Harness Code plug.? - the other half of the connector with the short jumper wires in it shown in your photo above. See Post #4.
2. Do you have continuity on the 7 wires coming into the half of CONN 13 shown in your photo.? Again refer to Post #4. Six of them go to the transmission control, the other one (202 Black) goes to machine frame ground.

1, yes correct continuity at the plug 2, no, only got continuity from #2 to #1,3,4, and 7. and only when +is on #2, no other continuity any other way, almost like there's a diode? #2 to frame is good,

Sorry maybe you misunderstood. I meant check the continuity of each wire of the six individually (e.g. 276 Black) from CONN 13 to the appropriate pin on the controller connector. In the case of 276 BK that would be to Pin 24. This would require the connector marked FF to be unplugged from the control. When you have done that check for a shorted harness by measuring the resistance between Pin 1 of CONN 13 and Pins 3,4,5,6, & 7 - again with the connectors at both ends unplugged. Lastly check for power on Pin 1 of the control with the key switch ON, and check the ground from the control connector (not sure which Pin) to machine frame ground.

Nige said: Lastly check for power on Pin 1 of the control with the key switch ON, and check the ground from the control connector (not sure which Pin) to machine frame ground. Click to expand... That would be power on Pin 1 and ground on Pin 2. It might be something that's already been covered but is the (external) transmission control fault light lit when the key is ON.? It's the small red one in the photo in Post #7 above.

Checked all from your last 2 post, all good,

OK, so now the next step is to test all the transmission solenoids. You should to apply Batt+ and ground to each pair of solenoid wires in turn at the side of CONN 18 (24-pin) marked "D" with the connector unplugged. So for example to test Sol #3 (FWD Low) you would connect power & ground to 923-Grey (Pin 12) & 754-Blue (Pin 3).

#4 solenoid not working, tried another solenoid on #4, same thing, not working, I will need to order parts, would this have caused the code? And no movement? Next step replace cartridge, clear code? And good to go?

wrightdj said: #4 solenoid not working, tried another solenoid on #4, same thing, not working, Click to expand... Try at least a couple more solenoids in #4 station that you know work in other clutch stations. If no solenoid works in #4 then somewhere in either wire 924-GR or 725-OR you have an internal break It may pay you to investigate the cost of a complete replacement harness. According to the electrical schematic the Part Number is 102-9298 which seems to be a good number. wrightdj said: would this have caused the code? And no movement? Click to expand... It could have. I'm not 100% sure at the moment. wrightdj said: Next step replace cartridge, clear code? And good to go? Click to expand... Why would you contemplate replacing a solenoid when you have installed a (hopefully) known good solenoid from another clutch station into #4 and it still doesn't work.? That's why I said above to try various solenoids in #4 and if none of them work you have conclusively proved that there is a fault in the wiring harness to #4. That fault needs fixing first before you can move on. There may be other faults to be uncovered once you have that one fixed...........

Sorry Nige what I should have said was #4 coil is okay, the Cartridge is not moving, the wiring is okay, I will switch it out with another.

OK, gotcha. Test with at least a couple of other known good assemblies. There is of course the possibility of a wiring fault not allowing sufficient current to pass through the circuit to move the cartridge even though the solenoid coil appears to be energizing. Attached the parts breakdown for the solenoid valve. Once you get the replacement installed then it's back to testing again. Don't assume that a replacement solenoid valve will fix all your problems.

I've been thinking back to the 605-02 Code. I think you need to do some more troubleshooting of that Code seeing as it's still there. Try this procedure with the 40-pin connector to the transmission control unplugged.

1. From Post #10 above you said that you already checked for a good ground on Pin 2 of the 40-pin connector.
2. I have arrowed four pins (24, 27, 28, & 29) in the 40-pin connector. If you follow the wire from each of those 4 pins it travels up through CONN 13 and to the splice in the Harness Code plug. From there a single wire goes back to Pin 2 on CONN 13, and from there via wire 202-BK to exactly the same ground point as the one service wire 202-BK coming from Pin 2 of the transmission control connector.
3. Connect one lead of your multimeter to Pin 2 of the 40-pin connector. Then connect the other lead to each of Pins 24, 27, 28, & 29 in turn. The result of each one of the four tests should be good continuity. Report your results.