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Bradley Martin
Bradley Martin,
Category: Construction and Road Equipment
Satisfied Customers: 174
Experience:  Field Technician at Thompson Tractor Company
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Cat 953c it's a 2zn, will not move forward or reverse. Ran

Customer Question

Cat 953c it's a 2zn, will not move forward or reverse. Ran fine when last parked
JA: We'll do all we can to help. Tell me a bit more about what's going on so the Construction Equipment Mechanic can help you best.
Customer: Machine motor and hydraulics good. Will not do anything in forward or reverse . Showing codes 030 248f02, and 079 168f02.
JA: Is there anything else the Construction Equipment Mechanic should be aware of?
Customer: 4000hrs on machine. Approx 200 since last service of pumps which included replacement by cat dealer
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Construction Equipment Mechanic about your situation and then connect you two.
Submitted: 7 months ago.
Category: Construction and Road Equipment
Expert:  catmastertech replied 7 months ago.
Looks like you have lost power to the transmission ecm.Please post the full machine serial number so I can research this deeper. The codes you have posted are for lost power, are they still active? (or just logged?)
Customer: replied 7 months ago.
Yes they are active. Sn# ***** I know I need to check power. But do not know where D1 and D2 connectors are located. Also cannot see how to disconnect Ecm to check connections. Does the ecm have to disassembled to disconnect? Yes, this does seem to be a voltage issue
Expert:  catmastertech replied 7 months ago.
Sorry for the late reply, I had to step away for a time. I am not sure what you mean by "Does the ecm have to disassembled to disconnect?"Do you remove the connectors? Normally, turning the key switch off and waiting ten seconds it the only "power down" the ECM needs. Some will hold power on a few circuits with the key switch off but, it is not require to disconnect anything. If you are having strange power issues, just turn the battery disconnect switch off and wait ten seconds. To verify all power is off and no shorts are in the system, turn the key on and to the start position with the disconnect switch off. You should not have any power to any system.
Expert:  catmastertech replied 7 months ago.
Why are you asking about "D1 and D2" connectors? Where did you reference this information?Are you sure about the codes? I do not see a 168F02, only 168F03 and 168F04.If it is 168F03, this means your alternator is overcharging and the high voltage will cause the ECMs to shutoff to prevent damage.
Expert:  catmastertech replied 7 months ago.
Why are you asking about "D1 and D2" connectors? Where did you reference this information?Are you sure about the codes? I do not see a 168F02, only 168F03 and 168F04.If it is 168F03, this means your alternator is overcharging and the high voltage will cause the ECMs to shutoff to prevent damage.Do you mean you want to check the ECM connectors J1 and J2? This is how I see them in the service manuals. Do you have a schematic or manual you are working with, is it correct for this machine?
Customer: replied 7 months ago.
Sorry it was 168 f04. I wanted to clean connectors to ecm per service manual, but could not see how to detach connectors from unit. Voltage at batteries at idle is 27 volts.
Expert:  catmastertech replied 7 months ago.
Each ECM connector has a 4mm or 5/32" hex socket screw attaching it to the ECM in the middle of the connector. The code you have is for low voltage. I would also check the inlet air heater to see if it is stuck on, I have seen this issue on wheel loaders before with this engine.
Customer: replied 7 months ago.
Service manual reference a voltage check at each D1 and D2, need to locate to check.
Expert:  catmastertech replied 7 months ago.
I could not find that in my manual, which book are you using? Troubleshooting for the powertrain?
Expert:  catmastertech replied 7 months ago.
Sorry, I just found it. It is talking about the ecm connector (J1 in my reference) at pin 1 and pin 2 for power and ground to the ecm.
Expert:  catmastertech replied 7 months ago.
It is the connector with the most wires to the ECM. The one with the fewest wires is the J2 connector.
Expert:  catmastertech replied 7 months ago.
This should be located on the right side of the machine.
Expert:  catmastertech replied 7 months ago.
Ok, I see why they call it a "D" connector. See attached image.
Expert:  catmastertech replied 7 months ago.
On this type of ecm, the screw is actually on the ecm connector and pulls the harness connector into place.
Expert:  catmastertech replied 7 months ago.
That is why I need to refer to the serial number. I forget which ecm is in each different machine.
Customer: replied 7 months ago.
I am using that cat service manual for 2zn1750 andup. Under transmission control systems, page 74, step 2 references D1 and D2. Wires 164 and 202 respectively . Located wires but not connection. Did not want to puncture wires, I am assuming D1 and D2 would give access with out damaging wires. There is no visible fasteners for connectors at ecm for connectors , therefore my question , are these only accessible by removing cover for ecm, which would require removing ecm. Again pet cat manual it has no reference this, and to the contrary says to remove connectors then ecm.
Customer: replied 7 months ago.
Question 1. Hou do you get access to retaining fasteners for ecm connectors?
Question 2. How can you check voltage for wires 164 and 202 with out damaging insulation?
Question 3. What are the possible causes for the voltage drop other than a bad connection. Would a bad sensor for pedals of speed direction cause this?
Customer: replied 7 months ago.
Where would I find the inlet air heater?
Expert:  catmastertech replied 7 months ago.
The step refers to using the 7X1710 probes, these will allow you to slide into the back of the connector and contact the pins inside.If you have any small needle contacts, this will work as well. The screw is in the adapter on the ecm opposite of the connector. It is the same screw used on all ecms. (4mm or 5/32 allen wrench will loosen the connector.) It is probably covered with dirt and a light cleaning or scraping with a pick will help you find the hex socket for the wrench to fit.The manual wants you to test the connection before disconnecting the connector but, you can do it either way.NEVER open an ecm, this will destroy any turn-in value for REMAN exchange if needed.I am sorry for the late reply, I had to step away again. I did dig through some other manuals but, could not find any better image to show the screw location.Sensors only use 5 to 8 volts. Even a dead short in a sensor will not draw enough power to affect the ecm.Look for high amperage draws like A/C compressor, fans or even the starter switch sticking and the starter motor staying engaged.The air inlet heat is in the air inlet on the engine. Between the inlet elbow and the intake manifold. Test the power wire for current and follow it back to the control relay if you find power is staying on the wire. This is usually a 4 gage red wire.If you find the power and ground is correct to the ecm, begin testing the data link code to the monitor. Normally, the data link codes will not stop a machine but, sometimes they do relate if both codes remain active.
Customer: replied 7 months ago.
Thanks You. I will check voltage tomorrow . I was concerned trying to put probe in connector, it just seemed very tight. Just hope not ecm.
Expert:  catmastertech replied 7 months ago.
Since it is reporting this code, I doubt you have any ECM problem. It is rare and always the last item I consider when troubleshooting.I have never seen this code related to an ECM failure, usually it is a voltage draw from somewhere else. Since your battery voltage is good, I would suspect your harness is damaged and the voltage is not going into the ECM wires correctly. (Or the ground is weak or missing.)That is why it is important to test the power and ground with the ECM connector still in the ECM. That will show you the actual voltage lost to the ECM. I have never seen any ECM be the root cause of voltage drop. I have seen a few bad ground wires and damaged power wires that were worn through and only had a few strands still connecting the ECM. You could see correct voltage disconnected but, not connected. If you suspect this is the case, make your own power wire and ground to the ECM. (This would require the tooling and parts from a Deutz harness repair kit though.)Let me know what you find. I will be glad to help as much as I can. Thanks, catmastertech
Customer: replied 7 months ago.
Just a quick update. It has been raining so my time has been limited. I am getting 27 volts on wire 264 (white) @ ecm if I ground to machine. If I ground to ground wire (204)@ecm I get a max of 10volts and 3 at fast idle. Appears that I have a bad ground too me. Do you concur? Can wire D2(204) be jumped directly to machine to verify? I did do a resistance check for this wire and it is minimal. Note that this machine has never been exposed to a harsh environment it is rust free. I do not see any grounds for harness. Any suggestions to check? Thanks
Expert:  catmastertech replied 7 months ago.
Thanks for the reply.Yes, this is a chassis ground wire. The schematic shows it connects several other ground wires and is actually grounded behind the dash for the monitor. Since you also had a monitor code, I would check the ground stud in the dash and also look for a ground strap from the cab to chassis. The dash ground should be near the center of the dash with several other black wires attached.The platform (cab) to chassis ground strap should be located at the left front cab mounting bushing.Just to verify, you mean the 164 white wire for power at pin 1 of the D connector and 202 black wire for ground at pin 2 of the D connector.The color should be the same but, the number can change on some serial numbers. Basically, all 100 marked wires are power supply wires and all 200 marked wires are grounds. (Some are floating and do not return to chassis ground however. These are usually higher numbers above 250.) If you need further help, please let me know. I will be glad to help as much as I can. Thanks, catmastertech
Customer: replied 7 months ago.
Yes d1 and d2 are the whit and black wires. Also marked on the connector as 1&2 so I feel comfortable about that. Thanks for the location info for the grounds, I will try and locate these tomorrow . So, If the ground is the issue at the ecm, I should be able to ground the wire D2 (black wire)to chassis and it should work? Or is it more complicated?
Expert:  catmastertech replied 7 months ago.
It should work fine, I am only concerned you may find another ground problem later if you just bypass this problem. Follow the harness from the ECM to the cab and inspect it for rubbed areas or damage to the harness. Maybe you will get lucky and find the break in an area that is easy to fix.The schematic shows the next closest ground is the Diagnostic connector (B terminal) and the service switches. All of these connect back to the dash and all of the dash switches ground to the same stud.
Customer: replied 7 months ago.
Thanks. I intend to find the initial problem , even if I gave to get car dealer do a service call. The last time this happened though it cost me over $10,000.00, for new pumps on a 3800 hr. Machine. Same events less than 200 hrs ago. Just wanted to eliminate that again. Thanks again
Expert:  catmastertech replied 7 months ago.
I understand, glad I could help.Feel free to contact me again if you need more help with this. P.S. Please remember to rate my answer to close this question. It is the only way I get paid. You can still contact me afterwards as well.
Customer: replied 7 months ago.
I will. Thanks
Customer: replied 7 months ago.
Machine will still not run. I have cleared prior codes discussed. Now I have code 299f13. I have successfully calibrated directional sensor three times and it will not clear. Any ideas? Could sensor be bad, and still be calibrated?
Expert:  catmastertech replied 7 months ago.
Sorry for the late reply, I am traveling out of town and don't have access to all my files at this time.The F13 code is just calibration and I have not seen one that cause the system to not work but, it is possible if it is working outside of the parameters.It may be worth a try but, I would also look closer at the parking brake switch. Use the monitor or ET to view the status of the switches to see if the ECM is seeing the correct operation of both. It is possible to have an open wire to a circuit that does not cause a fault code. I am assuming you have already ruled out a broken drive coupling and know the pump is making pressure.
Customer: replied 7 months ago.
Thanks for getting back. I replaced the speed direction sensor. This cleared the code. I have no codes and machine will still not move. I did calibrated brake successfully . It showed parking brake releasing and applied correctly.
What I did notice,while running in neutral the charge pressure reads 345. Once I increase engine speed and move the directional lever full forward ,the pressure increases to over 1300 and schedule 3 alarm goes off for charge pressure warning,but no codes. Not sure what this means. I did change filters just to verify no restrictions. I did clean the grounds,two,one behind dash the other beside horn. I have a field service scheduled for Friday. Can you suggest anything else that may cause this that I could check? Your help is appreciated. Note the hydraulics work fine,bucket ect.
Customer: replied 7 months ago.
Do you think it would be worth removing solinoeds and cleaning ?
Expert:  catmastertech replied 7 months ago.
Unfortunately, the hydraulic side is where I don't have any experience. I have made repairs to a few electrical issues but, I have not done any troubleshooting on the hydraulic problems.So I cannot offer any good advice that would be helpful. I would need to perform all the testing steps in the manual and see where that would lead me. I saw some info on an override valve and some problems with it but, It was describing too much pressure. I will OPT-OUT and see if another tech can help you.
Customer: replied 7 months ago.
Thanks
Expert:  Bradley Martin replied 7 months ago.
Have you put a gauge and on your brake and seen what the pressure is? also have you pulled the overide solenoid off and checked the valve for debris or blown o-ring also need to check power to the overide valve.
Expert:  Bradley Martin replied 7 months ago.
here are a few documents that might help
Expert:  Bradley Martin replied 7 months ago.
Any update today?
Customer: replied 7 months ago.
Thanks for the reply. I had field service tech. From local cat dealer out yesterday. He suspected a faulty charge sensor. One was not available locally. I have tried to remove unsuccessful . There are two nuts,19mm adjacent to valve body and a 16mm which appears to be part of sensor. I have tried to loosen both unsuccessful . Can you tell me which one I should be concentrating on? Thanks
Expert:  Bradley Martin replied 7 months ago.
Can you take a picture of what you are trying to take off?
Customer: replied 7 months ago.
Trying not to force anything ,but I did get off. It was the charge pressure sensor. I cleaned and did not help. If this means anything, if I run engine speed full throttle, and set full fast forward, machine will move for about 10 seconds at reduced speed before transmission and charge pressure indicators light up. Will not move under reduced throttle or reduced speed setting.Does this have any meaning to you? I have ordered a new pressure switch, but will not be in until Wednesday. Still no codes, any ideas? Unfortunately Cat tech had no other suggestions. I did state that his pressure readings for charge pressure, read correctly. Thank you..george
Expert:  Bradley Martin replied 7 months ago.
Are you saying that the charge pressure sensor is good or is it bad?
Customer: replied 7 months ago.
I am putting a new one in today and determine that.
Expert:  Bradley Martin replied 7 months ago.
Ok let me know what happens
Customer: replied 6 months ago.
Replaced charge sensor, still doing same thing. Still no codes. Any ideas?
Expert:  Bradley Martin replied 6 months ago.
Have you checked your connections at the ECM?
Expert:  Bradley Martin replied 6 months ago.
I will do some investigating when I get home this afternoon will that be ok
Customer: replied 6 months ago.
Yes . Cleaned both. Cat tech can't come back for two days. He said charge pressure is good when he hooks up gauges, but ecm is seeing low charge pressure and that is why alarms going off.Therefore he is thinking a bad ecm. But any suggestions would be appreciated.
Expert:  Bradley Martin replied 6 months ago.
Has there been any welding done on this skidsteer that you know of?
Customer: replied 6 months ago.
No. It's a 953c loader, never heard them called a skid steer. Ran good when parked several weeks back.
Expert:  Bradley Martin replied 6 months ago.
Sorry I was thinking of a skid steer. Any possible bad lighting storms while loader was parked?

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