Jeffrey Bandel
Senior Member
Great. I replaced the MAF sensor and it didn't solve the issue. Your advice is to check the harness that plugs into the sensor?
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CAT 299D won't move
- Thread starter Jeffrey Bandel
- Start date
Nige
Senior Member
That document I posted above is for jumper harnesses to address a known issue with not enough slack in the various sensor harnesses that were causing connection problems. I would go looking very closely at the MAF sensor harness on your machine, and especially at the connectors.
The 391-0251 harness does not appear for your Serial Number because it’s an upgrade over the original non-Deutsch connector harness that the machine was originally built with. It is a jumper harness that is provided to connect between the existing machine harness and the MAF sensor in case there is not enough slack in the original one.
377-6960 should be good for your S/N but without checking I’m not 100% sure. Normally I would never search on parts.cat.com under a S/N. I’d just go looking for a particular Part Number.
Edit: Without using a S/N I found both 391-0251 & 377-6960 on parts.cat.com. The price of the MAF sensor @ $250 is a bit tasty...!!
I think I would first check the values for +Batt (wire 150 OR) and Ground (202 BK) at the MAF sensor, then check wires N774, N775, & N776 for continuity from connector E-C39 right back to the engine ECM. Then inspect the end of the harness that connects to the MAF sensor. Is it pulled tight when connected or does it run into the sensor on a smooth curve with an acceptable amount of slack in it..?
Remember the highlighted bit from the Passive Sensor test procedure........ you have one code for a short circuit and the other for an open circuit, both of them in the MAF sensor "branch" of the engine harness.
The 391-0251 harness does not appear for your Serial Number because it’s an upgrade over the original non-Deutsch connector harness that the machine was originally built with. It is a jumper harness that is provided to connect between the existing machine harness and the MAF sensor in case there is not enough slack in the original one.
377-6960 should be good for your S/N but without checking I’m not 100% sure. Normally I would never search on parts.cat.com under a S/N. I’d just go looking for a particular Part Number.
Edit: Without using a S/N I found both 391-0251 & 377-6960 on parts.cat.com. The price of the MAF sensor @ $250 is a bit tasty...!!
I think I would first check the values for +Batt (wire 150 OR) and Ground (202 BK) at the MAF sensor, then check wires N774, N775, & N776 for continuity from connector E-C39 right back to the engine ECM. Then inspect the end of the harness that connects to the MAF sensor. Is it pulled tight when connected or does it run into the sensor on a smooth curve with an acceptable amount of slack in it..?
Remember the highlighted bit from the Passive Sensor test procedure........ you have one code for a short circuit and the other for an open circuit, both of them in the MAF sensor "branch" of the engine harness.
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Jeffrey Bandel
Senior Member
We checked E-C39 and didn't get 12V--so we replaced the sensor ($250 tasted bad). That didn't work. The harness had a smooth curve but hardly any slack.
I'm looking at the electrical schematic and cannot see what is between E-C39 and the engine ECM. Are there other connectors?
I'm looking at the electrical schematic and cannot see what is between E-C39 and the engine ECM. Are there other connectors?
Nige
Senior Member
Not according to what I can se. It's a straight shot between Connector E-C39 and the ECM.
I suggest that with the engine off and the MAF sensor disconnected, jumper pins 1 & 2 at E-C39. Then check the continuity of the loop you have created at connector J1 of the ECM
NOTE: The wires involved are 150 Orange (+12V) and 202 Black (ground). You can see a couple of large splices in the E-C wire harness of both these numbers at Grid G-14. In the same way as you tested for an internal harness short for the speed sensors a while back I would personally test the continuity of every possible combination of 150 Orange (6 locations) and 202 Black (7 locations) on Connector J1, so you would have 40+ tests to do. The reason I say this is that I have seen those internal harness splices fail in weird ways before. Just because you have continuity in one combination of wires 150 and 202 does not mean that you have continuity in all of them.
I suggest that with the engine off and the MAF sensor disconnected, jumper pins 1 & 2 at E-C39. Then check the continuity of the loop you have created at connector J1 of the ECM
NOTE: The wires involved are 150 Orange (+12V) and 202 Black (ground). You can see a couple of large splices in the E-C wire harness of both these numbers at Grid G-14. In the same way as you tested for an internal harness short for the speed sensors a while back I would personally test the continuity of every possible combination of 150 Orange (6 locations) and 202 Black (7 locations) on Connector J1, so you would have 40+ tests to do. The reason I say this is that I have seen those internal harness splices fail in weird ways before. Just because you have continuity in one combination of wires 150 and 202 does not mean that you have continuity in all of them.
Jeffrey Bandel
Senior Member
OK. It looks like you have to remove the engine ecm from the frame to get to it. Does that sound right?
Jeffrey Bandel
Senior Member
Are the connectors to the ecm labeled? Is J1 forward or rear?
Nige
Senior Member
I wouldn't have thought to.
You tested continuity on a lot of wires on J1 & J2 before. How did you do that..?
Question: Do you have a pair of "spoons" for your DMM to test wiring without the need to detach connectors.? You slide the spoon down the outside of the cable into the back of the connector until it touches the pin.
Search 7X-1710 on here. Cat ones are pricey according to some people but really good IMO, other options are available from places like Amazon for less. You pays your money............ https://www.amazon.com/Electronic-Specialties-616-Spoon-Probes/dp/B07Q2MZSYH
You tested continuity on a lot of wires on J1 & J2 before. How did you do that..?
Question: Do you have a pair of "spoons" for your DMM to test wiring without the need to detach connectors.? You slide the spoon down the outside of the cable into the back of the connector until it touches the pin.
Search 7X-1710 on here. Cat ones are pricey according to some people but really good IMO, other options are available from places like Amazon for less. You pays your money............ https://www.amazon.com/Electronic-Specialties-616-Spoon-Probes/dp/B07Q2MZSYH
Nige
Senior Member
It all depends on how the ECM is oriented in the particular machine installation. I always prefer to confirm the identity of J1 & J2 by using wire colours and numbers from the schematic combined with the Pin Numbers of J1 & J2 (which are marked on the back of each connector).
For example from your schematic wire 150 Orange is in Pin 1 of J1, and pins 2 & 3 of the same connector are empty.
Pins 1 & 2 of J2 are empty, with a Black wire in Pin 3. That ought to make identification of which connector is which reasonably straightforward.
Jeffrey Bandel
Senior Member
OK. Thanks. I need to get some spoons. Do you know what the little pins are called--the tiny ones that insert into the small sockets on J1 and J2? I attached small wire to the probe ends to test them before--it worked, but I've seen people use tiny pins designed for it.
On the machines ECM they were labeled J1 and J2. I can't see any markings on the machine ECM. I assume the forward one is J1.
On the machines ECM they were labeled J1 and J2. I can't see any markings on the machine ECM. I assume the forward one is J1.
Nige
Senior Member
If you go back to one of your very early posts (Page 3 post #42) with the photos of the damaged speed sensor wiring that you found I gave you part numbers of the Deutsch connector pins and sockets along with the P/N of a single-wire splice.
Also as I said at that time to install the pins/sockets correctly requires a Deutsch crimping tool that costs about $200. Now if all you want to do is crimp a couple of pins on some lengths of wire, here’s my thoughts. Buy the pins then go to the Cat dealer and have a word with the tech you spoke to before and see if he will crimp them on for you. All techs will have that crimp tool available to them.
https://www.amazon.com/Support-Size...nt=&hvlocphy=200539&hvtargid=pla-614976235628
Regarding your question about J1 & J2 all I can do is repeat how I do it in a machine I’ve never worked on before. Identify them using the wire numbers and colors specific to the machine - as per my post above it shouldn’t be hard to figure out which one is which. I try not to assume as it usually comes back to bite me on the a$$.
Also as I said at that time to install the pins/sockets correctly requires a Deutsch crimping tool that costs about $200. Now if all you want to do is crimp a couple of pins on some lengths of wire, here’s my thoughts. Buy the pins then go to the Cat dealer and have a word with the tech you spoke to before and see if he will crimp them on for you. All techs will have that crimp tool available to them.
https://www.amazon.com/Support-Size...nt=&hvlocphy=200539&hvtargid=pla-614976235628
Regarding your question about J1 & J2 all I can do is repeat how I do it in a machine I’ve never worked on before. Identify them using the wire numbers and colors specific to the machine - as per my post above it shouldn’t be hard to figure out which one is which. I try not to assume as it usually comes back to bite me on the a$$.
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Nige
Senior Member
Nah, we're nowhere near the record yet. That was the famous 62-page D6C engine thread ………. 
Jeffrey Bandel
Senior Member
The problem is solved. I tested all the wires and found no problems--but it still would not regenerate on its' own (it was at 100%). My CAT guy came out today and tested the wires-all checked out. He spent about an hour on the computer hooked up to the CAT to try and "manually" regenerate. It was stumping us (really him because I was just watching) but finally he was able to regenerate it. He is confident it is fixed. Also I replaced the right speed sensor--that fixed that problem.
So in conclusion, following the advice of the forum (Big thanks to Nige again) I was able to fix the problems, but they weren't actually fixed until a CAT computer was hooked up.
Now I have other problems to fix so hopefully I can lean on you guys again.
So in conclusion, following the advice of the forum (Big thanks to Nige again) I was able to fix the problems, but they weren't actually fixed until a CAT computer was hooked up.
Now I have other problems to fix so hopefully I can lean on you guys again.
Nige
Senior Member
Did you have the Cat guy erase all the logged Diagnostic Codes from the machine while he was there..?
It would make future problem solving much easier.
It would make future problem solving much easier.
Jeffrey Bandel
Senior Member
Yes. The only active code is the bucket tilt (I think that is what it is called). There is a broken wire that needs to be repaired. I'm not to concerned about it.
Jeffrey Bandel
Senior Member
My success was short lived. I got about 3 hours of use into it. Today, when I backed up, the parking light would come on and it wouldn't move. If I turned it off and back on, the parking brake would release and I could use it--until I backed up. It didn't do it every time I backed up, but at least every 4 times.
Nige
Senior Member
Based on what has transpired already, my money would be on the damage to the speed sensor wiring posted on your earlier photos. I may be wrong.
Jeffrey Bandel
Senior Member
I fixed all the wiring and it tested good. It could be that or the left speed sensor. Sure would be nice to have a display that showed the problem.
Nige
Senior Member
I get what you're saying, but from experience harness repairs to sensor wiring are a constant source of problems, because some of it carries either stabilized voltage or the ground for said stabilized voltage, and the rest carries PWM square wave signals. Neither of those two categories like being interrupted though splices too much.
The kit's gonna cost you a few dollars. Although TBH the way this is panning out you might be better biting the bullet on it sooner rather than later.
Jeffrey Bandel
Senior Member
How far back do you suggest replacing the wiring? Please don't say all the way to the ECM!!!