D5G LGP. Tracks will not move at all with light on dash and red flashing code 168. Any ideas? Thanks alot. Just replaced fuel pump, new batteries, rebuilt alternator showing good voltage, 14.3v. Recently had CAT mechanic replace fuel pump and blow out fuel line to tank due to engine stalling. Appears the tank lining, applied to prevent rust, is flaking off getting into fuel line. So then it was running good until I cranked it one morning and track gear symbol lit up immediately and dozer will not move an inch. Richie
168 refers to the engine coolant temp sensor. Why this should stop the machine in its tracks I'm not sure. See the attached. It might pay you to sort this problem before proceeding further but I'm not sure it will be the fix for your issue.
Thank you Sir, I remember the CAT mechanic did see a 168 code on his laptop but machine was running fine at the time.
As I said I don't think fixing the coolant temp sensor issue is going to make any difference, but until you do fix it you'll never know one way or the other. I wonder if it has stripped the drive coupling (#1 in the illustration below) between the engine and the Hystat, especially seeing as it happened at first startup one morning.? Not exactly an unknown problem. Post a Serial (PIN) Number and I'll take a look at what tests you can do to check for that. I think there should be a panel on the RH side of the tractor with test points behind it. Do you have access to pressure gauges.?
RKG00669 I do not have test gauges. Just FYI....the tracks did not lock up while running. It ran and move along properly one day, shut it down over night, next morning cranked it up and would not move at all.
That's what I thought I said. Often the biggest stress on that flexible coupling is a cold startup first thing in the morning, which is exactly what happened to you and then the park brake would not release. To test whether or not the coupling has failed is going to need a gauge or gauges hooked up to one or more of those test ports. A quick & dirty test would be on test port #9 (arrowed, bottom left) then start the engine and run at low idling speed. The pressure under those conditions should be around 320psi. If you have zero pressure then the coupling has most likely failed.
Ok. Probably be cheaper for me to buy gauges than a CAT mechanic to do it. Any idea of the simplest gauge kit to do these type tests?
New sensor is on the way. Would a stripped coupling typically throw a code?
Be prepared for the fact that a new sensor might not necessarily fix the 168 Code. You could just as easily have a wiring problem which will not be cured by fitting a new sensor. That's why I posted the troubleshooting procedure above - to help you determine exactly what failed...... See the highlighted parts. 2 couplings, a hose and a pressure gauge. Effectively those are the Cat Part Numbers that you would need to do a "plug & play" connection to Test Port #9. They will NOT be cheap to buy if you go to the dealer. HOWEVER, all you REALLY need is the 6V-4143 Coupler illustrated below. This (or an aftermarket coupler that will connect with the 6V-3965 fitting on the machine) is a must-have because it connects to the existing test port in the panel on the RH side of the machine. IIRC the female thread in it is 1/8" NPT but don't quote me on that. Here's a genuine one on eBay. Probably cheaper than the Cat dealer - https://www.ebay.com/itm/125154424305 Then you need a pressure gauge that reads up to 5-600psi maximum, and a hose (or some connectors) that will hook up the gauge to the quick coupler. Then you're all set.
Perhaps the correct port is #7 on my machine… pictured.
No it would not AFAIK. We've been there before on other D5G tractors IIRC. Read carefully through the two thread I have linked below. All the necessary information is there. The lack of pressure in the hystat system will not allow the park brake to release. I must admit to forgetting to advise you to test the alternator output voltage before proceeding further. This models is known to do weird things when the system voltage is not up to snuff. D5G XL Park brake came on when using Park brake came on when using, checked fuses, all good. No red light on by fuse box. Tried new brake switch and nothing. When switching from FED to REV the back up alarm comes on, running or just Key on. It will not start with switch in the parking brake off position. When turning key on... HeavyEquipmentForums D5G parking brake won’t disengage It started while I was operating it in reverse and when I crossed over neutral the parking brake engaged before I got it into forward… (I was actually looking at the dash and saw the light come on at that moment) after that I tried cycling the parking brake and nothing happens? First thought was... HeavyEquipmentForums
Gotcha. Thanks I priced the three parts new at about $270. Any reason this cheap test kit would not work? https://a.co/d/guEfzZj
No reason why it will not work apart from the fact that I don't see any connector in that box that will hook up directly to the Cat test point on the machine. You may have to buy the 6V-4143 separately.
Ok. I have learned the importance of proper voltage and yes it is putting out 14.3ish volts consistently with newly rebuilt alternator, belts and batteries. In my picture of ports above, is #7 the same as your #9 ? In the kit, I thought the connector they identify as being for “Caterpillar” would fit on machine, no?
OK, so we can rule that out. I'm sorry I do not know for sure. According to the manual for an RKG-prefic machine which is where I lifted that photo the test point I said should be around 32psi is #9. The thing to point out (after revisiting the first of the two threads I linked above) is that if the coupling has failed then there will be no pressure at ANY of those ports. Maybe, maybe not. The problem is that there are a few different styles of quick couplers on different product lines of Cat machines. Is it the end of the world if you have to buy one extra adapter over & above the kit in order to hook it up to your tractor.? Not really........
I do understand everything you’ve said. And I do agree, it would not be the end of the world. I have learned a lot here and really appreciate your time. A year or so ago I had the right final drive replaced. I noticed that testing the pressure ports was part of that process to check if pump was sending power to drive motor. I’m no mechanic at all but should be able to do that.
Just go slowly and if in doubt - ASK...!! looking again I think that MAYBE the brass connection in the photo might just be the one you need. it certainly looks as though it could be. The downside of that kit is the lowest pressure gauge in the set of three is rated at 3500psi max, not 5-600psi as required. For sure you're not going to blow up the gauge but when it comes to measuring lower pressures a 3500psi gauge is not going to be quite as accurate as a 600psi gauge. Maybe the best that you can hope for is that if there is any pressure at all at least the needle will jump off the bottom stop just a bit.
Thank you
I think those gauges pictured above read approximately up to about 700 psi, the thousands numbers are in bar. I think they would work okay for the lower pressures.
According to the ad linked by the OP the gauges are 250, 400, & 600 bar. That corresponds to 3500, 6000, & 9000psi. The set is really designed for excavator hydraulic testing. The 3500psi gauge ought to work for 300psi, or if as I suspect with a broken coupling the gauge will not move at all.
I got my pressure kit, Connected to and tested each port at idle speed. The only ports that showed pressure was #2,3 and 4 pictured with port number.
Can you try those three posts again. This time with the engine at High Idle RPM. Refresh my memory please. All the hydraulics on the blade (lift, tilt, angle) work OK, correct.?
I did rev throttle while connected. Needle moved just a little more, about one more line, 100 psi. Yes, all hydraulics work. I can try again in just a bit.
Going right back to your OP, I have a question. You said you have a 168 Code for the coolant temp sensor. Did you try scrolling the Codes to see if there was anything registered beyond the 168.? The Codes do not automatically display in order, you have to manually ground Pins 1 & 2 momentarily on the Harness Code plug to move from one to the next. See attached.
At high RPM those pressures should have been somewhere up around the 3000psi mark. See my previous question.
No I did not “scroll“ thru codes. Did not know of such. Just watched first code blink 168
OK. See the file attached in Post #24 above. Do the procedure as it is listed there and note each Code as it appears. You will know when you reach the end of the list because the first Code (168 I guess) will re-appear.
It certainly did not increase to near 3000 psi.
I jumped the pins and got codes 168, 124 and 426
124 - 8v sensor power supply. 246 - Right Track Speed sensor. Either of those could cause the tractor to fail to move. You're going to have to troubleshoot both starting with the 8v power supply because the track speed sensor is powered by 8v. Fix the 124 and the 246 might disappear on its own. See attached.
Attached the troubleshooting procedure for the Right Track speed sensor.
Hmmm. What do we have here?? This is connector to left motor thingy. Wonder if this could be the problem.
Is ECM in these pictures?
Yes it should definitely be fixed but the 246 Diagnostic Code you have is for the Right motor speed sensor. what you see there is (I think) the solenoid valve for the brake. I will check and confirm. The left motor speed sensor connection is those three wires almost out of shot on the left side of your 2nd photo. The Right sensor is hidden from your view on the front side of the motor. you will probably need a mirror or similar to check out the electrical connection.
It's up under the LH armrest right behind the left joystick. See the attachment Ref #20 (highlighted).
It's actually the solenoid that changes the angle of the motor swashplate to vary the ground speed of the tractor. See below. The speed sensor fits in the area of the circle and is secured by 1 bolt.
I have repaired broken wire and now unplugged the right speed sensor to visually inspect. All looks good. As per test #1 no ohms reading, passed I think Test#2 voltage of blue and brown wires. Should be 6.5-9.5v. FAILED. 4.3v is most I can’t get. Very difficult I’ll to get a steady signal in any of voltage tested. Test #3 testing other wires. Needs 4-6v. All wires were 4.88v passed. Apparently there is a wire/harness problem between sensor and ecm.
Do you mean that your meter registered 0 ohms, or did it display "OL" meaning there is a break in the ground circuit.?
It didn’t change from this pictured. I touched negative lead to everything I could.
One of these blue buttons will not stay out like I think it is supposed to. Fuse of some sort?
What happens when you touch the two probes on the ends of the red/black wires together.?
That is a circuit breaker (well actually they both are) and to the best of my knowledge the blue buttons should stay IN, not out. The button is supposed to pop out when the circuit breaker is overloaded. You press the button inwards to reset the breaker.
Ohms reads 0.06 The right blue button has spring action and will not stay in. Only when pressed. The left is stuck sitting awkward trying to get it out now.
If you have power off while trying to push it in it appears as though the RH breaker is popped and will not reset. 0.06 ohms, that sounds about right. Try unplugging ECM connector J1 and run a wire from Pin 70 (which is the other end of wire J764) down to the sensor connector. Then measure the resistance between Pin 2 of the machine side of the sensor connector and your temporary wire. You should get a reading not much more than the 0.06 that you got when you touched the probes together.
Scratch that. One is the main power circuit breaker, the other is for the alternator. Provided the electrical systems on the machine are all working and the alternator is charging there should be no problem with either of them, despite the fact that the one on the right appears to be popped.
I just found this exposed wire from rubbing aluminum band on hydraulic hose. Yellow wire under red rubber cap behind hydraulic filter and goes who knows where.
Interesting information from the operating manual for your multimeter............ If the resistance value exceeds the selected range value, a "1" will be shown on the display. The measurement range should be changed to a higher one. So try cranking the dial on your meter right up to the "2M" setting and re-measure. I suspect the results will be the same and it will still display a "1" but just want to confirm.
That's wire to the hydraulic oil temperature sender. Obviously the damage needs repairing but not associated with your current problem.
Same ohm reading when touch anything on machine I can reach other than the very edge of this box. Then it reads like .003 ohm
Looks like there is a bit of bare metal on that corner which would give somewhat of a connection to machine frame ground. Was the other probe of the meter in Pin #2 on the machine side of the speed sensor connector (J764 Brown) when you got that .003 reading.?
Pin was on brown wire at connector harness. Leaving dozer at least for now.
OK, so the sensor ground (Step 1) is good. Step 2 you previously measured 4.3v, which is low. I know it's difficult to get measurements because the sockets are in the connector are so small, but try sticking something like a paperclip in each of the contacts 1 & 2 of the connector.
Ok
Attached clips to probes and wires to blue and brown wires.
Definitely below what is acceptable. You need to go back to Post #30 on Page 2 and start doing the troubleshooting for the CID0041 Code for the 8v supply, because that's what Step 2 is looking for, 8.0 +/- 1.5v.
Is this ecm harness?
No. The ECM connectors are 70-pins and are located right on the ECM itself. Refer back to the pdf document I posted earlier of the platform wiring parts
“C. Perform the following measurement at the connectors of the ECM. Measure the resistance between the contacts for the +battery and the contact for the sensor supply voltage.” So at these connectors, one is +battery and one sensor supply? Any idea which ones? And this is one of two
I may be wrong but didn’t I send you an electrical schematic drawing.? Batt+ is on three Pins on connector J1 of the ECM - 1, 31, & 39. Wires are 308 Yellow, 126 Pink, & 126 Pink respectively. Sensor supply voltage is also on J1. Pins 44 (wire 497 Blue) & 69 (709 Orange). If you look on those two big connectors you can find the Pin Numbers are marked on them. They are right there in your photo. I always identify J1 & J2 by the different wire colours/numbers going into the different pins. This is especially true with your ECM which is installed upside down from the way it would be on most machines. The connector in your photo is J1 because it has wires in Pins 58-60, nothing in 61-66, then wires in 67-70. See snip below from schematic. If you have some aerosol electrical contact cleaner give both of those big connectors a good dose. They look as though there has been damp in them at some point in time. Also spray the ECM pins. It can't do any harm.
I plan to check those connectors tomorrow. Thank you very much.
Just a thought. Step 1 C is looking for a minimum resistance between two wires of 5000 ohms. Ideally you should be looking for your meter to read "1" which indicates there is no continuity between the tow wires you are testing. So set your meter dial to the maximum "2M" setting on the resistance scale. If the display shows "1" under those circumstances you are good.
Pins 1 to 69…..000 Pins 1 to 44…..000 Pins 31 to 44…. Screen goes blank Pins 39 to 44…..Screen goes blank Pins 31 to 69…..ditto Pins 39 to 69…..ditto When I connect those pins screen goes blank, as soon as I disconnect it goes back to 1.
I think you may have to get hold of another meter to confirm those results. Before that though, try dialling the meter down to the “2k” setting and try the tests again.
At 2k Pins 1 to 69…. 1. Pins 1 to 44…. 1.949 Pins 31 to 44…. Screen goes blank or -1. Pins 39 to 44…..Screen goes blank or -1. Pins 31 to 69…..ditto Pins 39 to 69…..ditto
I cleaned with contact cleaner. Now the blank reading are staying 1. or -1.
Do you see now why I suggested to clean those connectors, and also the ECM pins..? So the results of that Step are "OK". Is the RH motor speed sensor currently connected to the machine harness.?
It is not connected. Ru ro
Leave it that way and pull the Blink Codes again from the Diagnostic Indicator. Are the 124 & 246 Codes still present.?
Before checking codes again, I plugged sensor back in and checked all the pin ohms again. The blank screen came back. Unplugged sensor, connected ECM back and all three codes remain. Beginning to wonder if Cat mechanic has sabotaged my machine.
There are a total of 4 sensors that use the 8v supply. The two track motor speed sensors, the decelerator pedal sensor, and the brake pedal sensor. The location of the last two is illustrated below. Each one will have a short harness with a triangular 3-pin connector on it. Please disconnect ALL four sensors and repeat the Blink Code test.
Unplugged two new sensors. Now have three existing cords and two new ones. 252 and 254
252 & 254 are for the pedal sensors. It would be expected if you unplugged them. Are BOTH motor speed sensors unplugged.?
Affirmative
The reason I asked is that unplugging the LH motor speed sensor should also have created a Code - 251 in that case. I am more than a little surprised that it hasn't. I'm sorry but TBH I am now at the point where, without loading the parts cannon and throwing some parts at the problem in the hope of a solution, I don't know what to suggest next. The obvious thing would be a replacement RH motor speed sensor but the downside is that they are not cheap.
Thanks a bunch for your help
If you do bite the bullet on a speed sensor it is unfortunately not a "plug & play" replacement. On the existing 184-4584 sensor the connector on the machine harness plugs direct into the body of the sensor. The 360-0453 replacement sensor has 4 wire pigtails and requires a receptacle kit plus 4 pins to adapt it to the machine harness. A pin has to be crimped on to each wire pigtail. See the attached article.
Does that mean the original sensor is not available? Only the new style replacement? Does this look like one of them?
Is this not the new four wire sensor? Right and left sensor look the same. I had either one of both replaced about 10 years ago.
This is on both plug connectors.
Both the former and replacement sensors are 4-wire. The difference between them is that on the former design the connector on the machine harness plugs directly into the body of the sensor, as per your photo. On the new design sensor it has 4 wires coming out of the sensor body and the machine harness plugs into a connector that you have to install on the end of those wires. Hope that makes sense. The former Part Number 183-4584 is no longer available from Cat. It has been updated to a newer number as mentioned above. The former Part Number had a habit of leaking oil from the motor into the sensor body which would result in the sensor not working. Your photo shows the former design, I assume it is an aftermarket part. If what is in the box is the same as the photo it would be plug & play on your machine. IMHO it all depends how much faith you have in non-OEM electronic parts. Oh, and if you remove a motor speed sensor from the machine be ready to catch some oil because it will spill.
Ok. Thanks
Just a thought, last time I had sensor replaced, the machine didn’t go in neutral/park like now. It would just steer and move slowly.
Sorry for poor photo quality but this was installed on a machine. This is what the new P/N sensor from Cat looks like. The body is square with the wires coming out to the right side then round in an "S" shape to meet the connector plug of the machine harness in the rectangle.
Sounds like it could have had oil in it. It wouldn't be surprising for it so emit an incorrect signal as opposed to failing completely.
Ok. I just attached all connectors and still get same three plus the 252 And of course put everything back together in order to access those two plugs
252 is the brake pedal sensor. Should disappear when reconnected. Give both halves of the connector a squirt with contact cleaner and try again, or maybe it is not plugged in fully.?
I did spray it before connecting but perhaps not seated fully. I have a $200 plug n play sensor on the way from ConEquip.
Nige, do you know which one of these parts are throwing the 168 code? The part with long prong is located at top of radiator, which is what I thought would be the "coolant temp sensor". Not sure where other one is located. Thanks
It's the one located at the top of the radiator - 191-6587. If you are planning on replacing the sensor be aware that you could just as easily have a wiring problem. Why not try this diagnostic procedure and test whether or not the sensor is actually bad before buying a new one that may or may not fix the problem. FYI the O-Ring seal for the sensor comes separate - 153-4906.
I will test temp sensor. Thanks
Temp sensor harness test showed 0.00 volts with ignition ON. With that it passed the test resulting in replacing sensor.
Nige, I installed new speed sensor. Cleaned sensor pins and harness connector. Plugged her in. With ignition to ON and when engine cranked, I get codes 168 and 124....over and over. At least for now the other code, I believe was 426, is gone. In post #29 and #30 of page 2, I typed the code as 426. You responded as code 246 as being the right track speed sensor. Which was the typo? Thanks
Mine was the typo, and for that I must apologize. I was convinced that it was 246 and had to go back and look at Post #30 again to confirm that it was not. Code 426 is related to the circuits for the 8-pin connector that you pull apart to read the Blink Codes. If it has gone for now then hopefully it is nothing to worry about. Again my apologies for steering you in the direction of the RH motor speed sensor. Did you get anywhere regarding troubleshooting the coolant temperature sensor.? Not that it would stop the machine from moving but if you could fix it and the 168 Code disappeared at least it would give you some confidence that the troubleshooting procedures work and that you are moving in the right direction. The 124 is worrying. That is related to the 8v sensor supply and AFAIK it will stop the machine if that supply is not working as it should. I know you found nothing in your tests. Maybe it is time to get someone with Cat ET diagnostic software to hook up to the machine and take a look.?
Well I appreciate your efforts regardless. The 426 code disappeared for some reason after replacing the speed sensor. With my luck 426 will appear again. Based on the volt test on the temp sensor, it needs replacing but I haven't ordered the part yet. Dozer still will not move an inch. I will probably do the 124 troubleshooting again, I guess. The very last option is to hire a Cat mechanic per hour, and his truck per hour, and his truck transportation both ways and their mysterious $83 miscellanous fee, etc. etc. But I may have to.
The other (likely cheaper) option would be to find a local independent mechanic who has ET. Its use is not limited to Cat dealers.
The results in ohms testing harness pin connectors either make ohms buzzing sound and or less than 5000 ohms. Am I reading this correctly that the ohms are less than 5000 therefore there is an issue with harness OR does ohms sound indicate no resistance at all? “NOT OK - The resistance measurement is less than 5000 ohms. Repair: The machine harness has failed. There is a short between the +battery circuit and the circuit for the sensor power supply in the machine harness. Repair the machine harness or replace the machine harness.”
Wonder if this could be the problem. ? It is coming from wiring left of battery I taped it up and still has 124 code
Can you identify the wire number on the Pink wire in the front left of your 1st photo. I think I can see "41" but the 3rd number is covered by dirt. With the wire number the connector, and which circuit it feeds, can be traced.
I've never used a meter like the one you have so it's hard to tell. If you remember earlier I poisted a link to the user manual for it. Does that give any clues.? If not then I suggest it might pay you to confirm your results using a different meter.
414 perhaps
614
All three here
Found it. what I thought was a Pink wire is actually listed as Purple. CONN 23. It's part of the circuit for the heater/aircon blower motor. The 124 Green wire is live all the time the key switch is in the ON position. Check for a blown blower fuse.
All fuses on panel look good. Blower motor and A/C work
OK, so it looks as though it didn't blow the fuse which is somewhat strange but hey ho, back to tracking down the 8v sensor supply issue issue
I guess that means it is somewhere in the wiring harness. And so much of it is not in halfway reasonable sight.
From my way of thinking I'd like to see the resistance readings confirmed using a different meter before condemning the harness.
Ohms set at 200k 1-69…. -75.6 1/44…. -76ish 31-44….OL 39-44….OL 31-69….-49 39-69….-49
Try setting the ohms switch at 200 (instead of 200k) and see what results it gives.
All OL
In that case they are all showing open circuit, therefore greater than 5000 ohms, so they all class as "OK" on the resistance test.
“….and replace ECM if can’t find problem.” Crazy crazy how this dozer just decided to throw codes and not move.
Which is why IMHO you really needs a second hands-on opinion before shelling out for a replacement ECM that is probably priced somewhere North of $2k, plus labour to install. Any welding repairs been done on it recently.?
Nope. Only thing is a day before this happened I had a Cat mechanic replace the fuel pump and blow out fuel line to tank. Ran good for 30 minutes or so then started stalling out again like before line was cleaned out.Then next morning would not move. Makes me think a mouse chewed the wrong spot to have system be affected so quickly and overnight.
SOLVED Apparently the problem with my D5G Cat dozer is solved. Due to fault codes showing low voltage in one of three places, the transmission would default to neutral and tracks would not move. one of those places being the speed sensors. When unplugging the left speed sensor, the tracks moved. When plugged in tracks would not move. Replaced the left speed sensor and all is good.