Hi Folks, I think my Engine ECU crapped out. My operator was running the machine when the alternator let go and he drained the battery's walking it out of the woods. Now it wont fire up. No smoke when cranking I think its something in the ecu not allowing fuel the motor. what do you guys think. Original from volvo $3700 or aftermarket for $850. anyone out there have that have had problems with aftermarket ecu, big price difference between the two. All the volvo service guy said is buyer beware. thanks
Good day Have you tried switching into bypass mode to see if it fires up? Kind regards Uffex
yes. still no fire the vecm was replaced 4 years ago. I think its the ecm, thats what turns the fuel on and off. I don't know what inside the ecm that could of blown when the voltage dropped very low.
Good day Attached the diagram to check out before you go down the line of renewing parts, please excuse if you already have done so. Kind regards Uffex
I have no idea why an ECU would be the problem here. Don't buy an aftermarket.........and don't buy a new ECU until you troubleshoot the problem and prove its bad. Those don't fail easily. We need to expert Volvo guys here!
Post all codes and I will try to look them up for you. I don't have my laptop here with me so it would be some time tomorrow. You can buy a aftermarket ecu, but it will not have software. That only comes from Volvo. So the dealer will still have to program it. I can't remember for sure with your model. Even if you get a ecu from another machine it will not work. Volvo programs these in a way that if the other controllers don't recognize the new controller it won't start. These ecu's do fail and Volvo's ecu's fail more than any other brand I've worked on. I just replaced a engine ecu that was fine in every way except that the driver for the ground to the injectors failed. But it threw codes for the injectors and after I eliminated any other failures I replaced the ecu.
Funwithfuel May chime in he da Volvo genius lol
I was communicating with him in DM . I'm waiting to see how things shake out. Haven't heard anything after new batteries and alternator. Maybe he's got it straightened out. Southernman13, thanks, but I got a long way to go.
LOL......whatever! Your royalty with MG, Nige and a few others. The rest of us are mere peasants.
Sorry for the late reply, It was a crazy evening. I had the chance to look over a a couple things I found that by the fuel tank near the relay box there are two 80 amp fuses. The top one was blown. I couldn't get any codes because the monitor by the right arm rest is no longer working it worked before this problem . I removed the ECU and looked inside for any obvious issues I attached a pic. I noticed that a couple chips where crooked. I don't know if this is normal but it doesn't looks like it right. I will replace the fuse today. Any body have have any thoughts on the ECU Picture.
Those are 5v power supplies. The only concern is that they got overheated. If you have heat conductive paste (for heatsinks) you might wanna squirt some beneath the chips. The conductors seem to still be firmly soldered. I wouldn't sweat it just yet. Please post a pic of your instrument panel so we can provide you with the next step.
Now my panties are all wet I pick n choose my battles. Unlike you, you're like a mercenary fighting all battles for a buck.
The instrument panel by the window lights up as normal and is working, but the monitor by the arm rest is dead no lights. That usually tells the RPM voltage and trouble codes.
LMAO......so basically, I'm a HEF HO! I'll take it!
So, with what you are describing, you have the analog instrument panel with the red LED MDU. Now we're getting somewhere. (Without pictures) Above the battery box is a 4 bolt plastic cover. Remove that to access the relay box. 5 or 6 6mm screws to get inside. Be cautious removing the cover. The guts might have all come apart . You want to check relay for EMS and DATA. swap out with horn and high speed travel for testing. Later, I will post up active and passive measuring against the ECU inputs and outputs.
Please check the fuse panel , are any fuses failed, particularly #12 iirc? Or 21? It's been a long time.
Most of the fuse panel is dead. I noticed earlier today that the 80amp fuse under the relay box on the fuel tank was blown. I replaced it and it pop again. Any ideas what might make it blow.
This is a pic of the fuse.
First, lets look beside and under the boom foot. Any tools, shovels or rebar that doesn't belong? Now let's look at the cabling entering the R/S floor. Raise the seat all the way up and forward. Slide the platform forward first, then the seat. Where the cabling comes up through the floor, look at the grommets for burns, also check the oblong pass-throughs as well as where the cabling is clamped by P-clamps. These are possible places where the cabling may have rubbed or shorted.
As FWF is saying, to blow that fuse there has to be a major short somewhere or a reverse feed, I know it's a daft question and will probably have been the first thing you did check, BUT have you checked the batteries are on the right way round and/or that the polarity has been marked correctly on the batteries, stranger things have happened
A further though, did anyone try to jump start it with jumper cables?
I Found the Problem. A wire that came from the alternator had worn thru and was grounding out blowing the 80 amp fuse that powered up most of my fuse box. I Appreciate The help to point me in the right direction to resolve the problem. Thanks
Now I gotta wonder if the alternator was hurt after all. No field, no charge.