Hi, Our L90E stopped working after a 15 minutes paus. Working with no problems and then will not start. We get "Warning ECU Problem" and the instrument cluster is peeping. We have run a diagnose on it and we get communicating problems between the V-ECU and the E-ECU. We have checked all wires and they are ok. Anyone had simliar problems? Where can you get a used E-ECU? Cheers from Krister in Sweden
Check relay 15ea it should be i-ecu dependent. That powers up engine and vehicle ecus I think on your board would be RE10 Check terminating resistor behind instrument panel. It is a small 2 terminal plug that is wrapped in vinyl. Inside is a 120 ohm resistor. If you leave it plugged in and back probe measure you should see 60 ohms , unplugged should be 120 ohms. Do this with power off. At engine ecu on back bulkhead, check connectors. Disassemble and inspect. There are 2 twisted pairs orange yellow grey and green. Loosen the wires from one another make sure none are shorting against one another. Good luck
Thank you for the quick reply. The I, V and E Ecus seems to get power, I can communicate with the ECUs on the J1708/J1587 bus. (Diagnose IB socket for VCADS). It is VCADS that tells me that there is communication between the I-ECU and V-ECU but not between the E-ECU and V-ECU. I will check the relay and the terminating resistor and get back. We have messured the bus cables from the electric panel behind the seat to the E-Ecu and they show no short circuit or broken leads. I will double check the resistance again on the bus leads when the E-ECU is connected. At the moment we have removed and opened the E-ECU but there are no visible sign of problem in it. A repair site we spoke to said that they have had some E-ECUS that needed a reload of the software, there were no electrical problems in those units "only" software. Thanx
OK now knowing that you have v cards Perform a vehicle identification test if you can see software and data set levels for each then you don't have a software issue. If you see only a hardware number and date of manufacture but no software numbers and no data sets then that ECU software is corrupt. The software loss goes back to the concern that I was trying to steer you towards. the instrument ECU if the original part number or the hardware number ends in 402 there was a problem in the early production with a cold soldered joint. When you turn your Ignition switch S1 to position one it turns on a relay which powers up your instruments ECU the instrument ECU sends power to a second relay which powers up the engine and vehicle ECU this is for delayed shut down it is so that software can be shut down properly before the machine shuts off you want to investigate your delayed shutdown circuit if your software is missing
Ok very good, now I really have something to investigate! I have noticed that when I switch off the Ignition switch, it takes a couple of seconds before everything turns off and the I-ECU stops beeping. I have the E-ECU here on the desk, the numbers on it is: On front side: E00780147, VCE54001231, D6D LAE2, 05.12.02, 08:13. On the back: 03161983 P03, 80907C, 03161983, 00529932, 4602
Another thing to be mindful of just because you can identify the ECU's using the AL deal or 17/08/1587 connection This does not mean to your J 1939 CAN network is in good order You will have to disassemble carefully and inspect the to individual connectors at the engine ECU connector again you are looking for the twisted pairs in the top corner opposite one another all by themselves with colored wires Typically the engineer's you is a very resilient piece of equipment however as mentioned before the instrument panel is typically been shown to be the weak linkBetters way mention the part number or hardware number for IEC UMID140 If that part number and June for 02 and not 911 that may be the source of your problem
I will check the bus leads again for short or open circuit and messure the resistance in the cables. Will get back with the numbers on the I-ECU, will also open and check if I can see something strange in it. To be honest I did not suspect the I-ECU to be faulty since the I-ECU and the V-ECU seems to be very much alive. I´ll get back asap after my visit to the machine. It is about 40km away from home, outside and at the moment we have about -20C so it is not the best day to troubleshoot but I´m very intrested to see what I can find.
Well, if you could make use of the time, take a moment to review the schematic showing the I-ECU dependent relay as well as the relays involved. You will see one wakes them up, the other gives them power to work with.