Now my EC240B Volvo excavator is showing no signal to EMC on the monitor. I have (in the past year) replaced the monitor and the vecu. Then had problems with it running very rough and found bad connection on the main plug to the engine wire harnest. All was good for a while and now I have to wiggle the computer over ride switch under left arm rest for the starter to crank the machine. I have the switch ordered but I'm afraid it won't solve the problem with no signal. Any suggestions on where else to look?
Mack the switch you describe is not unknown to break a connection on the underside this could give the issue you are experiencing. KR Uffex
I have replaced the auto/manual switch now. At first I had no signal showing on the monitor. After fooling with it that message is now gone. Next problem is I have to select manual mode in the auto/manual switch for The starter to crank the engine. After I start the machine I go back to auto mode and I don't have any rpm with the switch on the right side of seat to set the work mode. The 3 position switch ( one beside the auto/manual) will let me rev the engine up no mater what position the auto manual switch is in. Please help.
Machine serial number? Have you checked all your fuses? Do you have power to the auto/manual switch and going out of it?
Serial # - EC240V80195 I have checked all fuses behind the cab next to the eecu. I do have power going to the auto/manual switch. Messing with it some more this evening the no signal would show back up on the monitor. I will turn the key back off and then it would go back to not saying no signal and having no error on the monitor. The only way I can start it is go to manual before turning the key to start. Auto just want let it do anything.
What is the message displayed on the IECU word for word? Have you checked to what fault codes are stored/active on the machine? You state you have batt voltage to the switch but do you have it going out and if so do you have batt voltage at connector B pins 15 and 16 on the VECU? Are your grounds good (Conn B pins 7 & 8)? How are the connectors going out the back of the cab any corrosion? Does the fuel gauge work?
Sometimes it will come up "no signal to ecm" I'll cycle the key a few time and usually it will go away. I did get a code on it . ---- 140 sid. 250. 9 On the auto/manual switch you have 6 wires , the 2 in the center have voltage. One is 26volts and the other is only 13 volts. I have the same voltage going through the switch per side. only 3 differ connection behind the cab below the e-ecm. The fuel gauge only works when it wants to. The pin you talk of will check and see .
You should have batt voltage coming in on connector 5 and out on 4 with the switch in auto mode. If all this checks out you have an issue on the information communication bus.
What about 1and 2 on the auto manual switch. Should that be half the voltage on that side? What can I do for the communication bus?
In auto mode that side of the switch is to control the PWM on the hyd. pump. That is controlled by the VECU. In manual mode current goes from 4 to 6 and then in on 2 out on 3 and then to the PWM on the pump back through a resistor and to ground. In auto mode the flow from the VECU to the PWM is from pin 2 to pin 1. So don't worry about those pins just yet as they will not cause the issues you are seeing. As far as the Can bus circuit. You are going to need a schematic and test for shorts between hi, lo and ground as well as opens between the ECU's. You are getting into territory that will probably be best served by calling your dealer. If it is a can issue it could be an ECU or harness either way not an inexpensive fix. But you still have not said whether you have voltage on pin 4 in auto mode or on pins 15 and 16 on VECU connector B.
Sorry for the delay . I've been out of town for last few days. I will check the pins tomorrow and post what I find. Thanks for helping me with this.
Ok With the key in the on position and the auto/manual switch in the auto position i have 24 volts on pin 2 and nothing on pin 4. On the V_ecu B connector pin 15 and 16 I have 24 volts with a ground on 8. Don't make sense to me.
I am so use to placing the auto/manual switch to manual before I start the machine now. But earlier when I had the switch in auto and turned the key on to check power on those pins 4,15,16 I noticed a new code came up on monitor. It is 187 sid 252. 2
hi Mack4255, your original code 140 250 is in relation to the can bus and could cause most of your problems I tried to find code 187 252 but is not valid for that machine. possible miss print?
More than likely the code you are now seeing is 187 251 1 which for low power to the VECU on VB 15&16 which you would get if you remove dthe B connector and keyed on. If you have batt. voltage on 15&16 all the time and ground on 7&8 you should be OK there. The next thing would be to troubleshoot the J1587 bus or data/information link. You can measure this at the diagnostic connector. That way you can get a measurement with all the ECU's in circuit but also be able to unhook 1 ECU at a time to eliminate ECU's as the issue. You will also probably need to unhook all the ECU's and and check for continuity in the circuit and for opens and shorts.
This is definitely getting over my head now. i may play around checking what I can since the next 2 weeks is going be slow because of the holidays . I'm going see what I can find in the book on checking B4 and B12 for that j1587. I'm open to segestions on how to do that. I really do apreaciat the help y'all have given. When I give up I'll have to send it 150 miles to the dealer.
Maa EnginsTP a partagé un fichier avec vous. drive.google.com