EC240BLC Wiring issues (2007 Year model) Volvo tech came, looked at the machine for less than 5 min and stated that the machine needs a wiring harness and sent a quote for about 20k to rewire the machine. They were no help. I've taken off every panel and looked at the wiring the best i can and do not see any obvious issues with chafing, or exposed wires. I-ECU will power on Intermittently - 1 out of 100 Times V-ECU - Replaced 05-01-2024 / did not correct issues(yes it was programed to VIN) E-ECU - No Known Issues No codes are known because I-ECU Issues, next time i test and I-Ecu will turn on ill update with codes. So when the key switch is turned to the on position, sometimes the I-Ecu will power on. The machine will turn over and start. From there it will not do anything. Sometimes the machine will go into manuel mode, other times it will not. no Responce from any input(joysticks). I do have wiring diagrams and pin information from Volvo(purchased all manuals) (no data for testing circuits) Battery cables were cleaned, Battery ground was cleaned. Batteries are fully charged. Tested the Grounds and power wires to the I-Ecu and V-Ecu and they tested good. Tested the Communication wires that connect the I-Ecu, V-Ecu and E-Ecu and they tested good. (no data for testing circuits other than they test good from end to end, no short) 1) Is there a Body Ground located inside the cab that the V-Ecu connects to that could cause intermittent issues? 2) Is there a hidden connector I'm missing ( connectors at Ecu's look good) 3) Does anyone have individual circuit testing data 4) Where do i need to go next? What am i missing?
Sorry I cant be of much help but hopefully someone on this forum may be able to give you some insight into testing and sorting the issue. Is it possible to remove the I-ECU and bench test it with a lab power supply ?
Please post your serial number. Additionally what your fuse box looks like. There are several different B-series configurations. The production year doesn't mean as much as the serial. BTW, have you investigated the relays and harness connectors immediately above the batteries?
Sorry have been out of town I’ll update with photos tomorrow and vin number
Does the machine function properly in Manual mode? At a minimum the tech should have or you will have to go through the active and passive measurements for the IECU and VECU. That will give you the best information to determine what is at fault.
Sorry it took so long to reply. Here is the requested information. I have not had a chance to work on the machine. While going through wiring I’ve found a couple unrelated issues. (Broke sensor wires
Tested the Grounds and power wires to the I-Ecu and V-Ecu and they tested good. When you say you tested the ground and power wires how did you test them? Do you have 24v at C5&C6 on the IECU and do you have a good ground at C10? Did you test with just a voltmeter or did you use a test light as well? A test light is better at telling you if there is enough current available. A voltmeter cannot provide a load on the circuit. It can only read potential. C5 is battery power through Fu24 and C6 is ignition power through Fu11. C10 is frame ground which should be behind the cab. The VECU should have 24v on B15&B16 from Fu07 and the manual mode switch. You should also have 24v at A35&A60 from Fu18 and A33 from Fu26. Grounds should be B7&B8 If you have the correct service manual all this info will be in it as well as the description and measuring procedures. If you have a manual for an older T2 or non IECU machine it will not be correct. It is hard to tell by your pics what wires and how many are compromised so you will have to do some testing.
@Ben Witter Thanks for the info So I was doing component testing on the I-ECU I pulled the back off the I-ECU and was testing the power board with a test light(incandescent) I discovered that when I touched C6 the I-ECU powered on and went back off. When I held the test light to C6. I gained full functionality of the I-ECU. So I was able to pull the codes from the machine. My theory - for some reason the increased resistance from the bulb allowed the IECU to detect the power signal and boot up. Due to c6 not being an actual signal wire but a constant power wire(key on). I’m thinking my I-ECU is bad. Feel free to correct my 1st grade electrical knowledge lol Also I included the codes. I’ve done some initial research on them. Haven’t had a chance to dig in to them yet. 140 SID 250 9 140 SID 254 9 140 I believe is the designation for the IECU. So I still feal like i have a component issue with the IECU. Any advice is greatly appreciated. Thanks again for your help so far
If your test light was connected to ground and you touched C6 I suspect you have a bad connection at the IECU or internally. If the ground lead on the test light was connected to positive then it could be inducing power to the IECU and causing it to power up. The ICEU's have a history of going bad due to their location and exposure to the elements, spilled coffee cups included. I doubt the resistance of the bulb had anything to do with the IECU powering up. More likely a cracked solder trail or bad connection.