My 315sg backhoe serial no T0315SG941798 stopped running it turns over but doesn’t fire,I checked the fuel system is fine, no active codes, I checked the wiring harness best I could looks good, I replaced the crank sensor didn’t fix it. When I crank it no rpm’s show,model 315SG shows on dash.book with spanner light comes on.could someone give me some directions where to look. I don’t have a manual are there any electrical test I can do? Cheers
Welcome to HEF Mesa ! No crank signal will prevent start up, which is indicated by the dashes in the reading. The book means there is a code. All your fuses good? Check your PM.
Hi, I tried the monitor service code procedure. It didn’t work when I got to step 4 the RPM comes up not the hour meter no dIAG. I have been accessing codes by pressing menu, select codes, select active. F9a3, F9c4 are active codes but I think these only appeared when I unplugged the ignition switch.
Both of these codes indicate that the CAN messages are not getting from the ECU to the monitor.. Did you check all the fuses? Need to make sure the ECU has good voltage supply (switched and unswitched), and a good ground.
I checked all the fuses in the front console, I don’t know if there are others elsewhere.
Then you need to check voltage supply and grounds at the ECU. Check your PM for the ECU pinout. Carefully back probe the wires and check the voltages and ground. Ground should not exceed 0.1 volts. If you have a good switched and unswitched 12 volts and a good ground, then we will need to look at the communication wires.
When you say un switched does that mean 12 volts all the time? And switched does this get power when you turn key to on position? I take it the ECU is the black box near the injector pump. Will check tomorrow.Thanks for taking the time to walk me through it.
Yes and yes. And yes again.
Ok Un switched 12.45v Switched 11.47v R14 1 blk Earth good, no voltage there 3D l grn wire 3.09v when ignition on 2D yel wire 2.02v when ignition on Did you circle R22 blk ? I had no earth. Cheers.
Sorry, I circled the wrong terminal. You want connector position J2 with the G40A black wire. That is the ground for the ECU. With the key off, what is your resistance measurement between the green and yellow wires? Also, check continuity (with the ECU and the Monitor unplugged) of the green wire and yellow wire between those components.
The G40 earth was good. I will check green and yellow tomorrow. Will the green and yellow be colour coded and easy to spot at the monitor side?
Lots of yellow wires at the monitor. You want the yellow wire marked M12 and the green marked M13. They should be the only ones twisted together.
The G40 earth was good. I will check green and yellow etomorrow. Will the green and yellow be colour coded and easy to spot at the monitor side?
Ok The resistance between yellow and green was 63.3 ohms and or 0.058 when multimeter on beep mode. And this didn’t change when monitor was unplugged. Good continuity for yellow when measured between monitor and ecu plugs and same for green. Cheers
63 ohms is what is expected. If the ECU has good voltage supply and grounds, and there are no issues with the M12 and 13 wires, then maybe your ECU is dead?? I am curious, if you measure the F1 and G1 terminals for resistance in the ECU, what do you have?
Ok news F1 to G1 is 36.78 ohms, is this in spec? I checked continuity on B2 and D2 the crank sensor wires, all good. I plugged everything back together and machine starts. When you turn key on the gauges go to maximum then down to zero then up to value but when the machine wouldn’t start the gauges would go to maximum then down to value, does the missing step point to the problem? I take it I have a loose connection or damaged wire somewhere? I really appreciate the help mg2461, there are no competent auto electricians where I live and the JD dealer is a agricultural one only interested in selling ride on mowers and gators to the well healed.
Bingo! You disturbed the wiring. So either you have loose terminals in the connectors, green growth and corrosion in the connectors, or a bad wire somewhere. There is no published spec. I will compare it to one I have in the shop. Typically on controllers, the "CAN" transmitter will have something in the Megohms. But that controller is fairly old technology. That is why I asked you to check it. Just for my curiosity.
The backhoe is very tidy has only 4000 hrs, I park it out of the weather, all plugs and terminal are like new. Any ideas which wires would cause it to stop? Is there a way to clear the stored codes?
Yes, check your PM.
That information says there are 2 types of monitors I think I have the other type as that procedure didn’t work for me , does that sound right?
Post a picture of your monitor. Has the monitor ever been replaced?
Post a picture of your monitor. If it is the one I am thinking of, you press and hold the menu button for approximately 5 seconds to enter the Service Menu. Then, scroll to codes. Press select. Then you have the option to clear codes.
Ok will do tomorrow
Pic of monitor
The instructions I gave in post #23 will get you to the codes and ability to clear them.