mdixon

So there may have been some error on my part, after testing the relay I reinstalled it and checked the wiring on start and got 12v. Rehooked the wires up to the starter relay on the starter and it fired right up. 

Maybe when I checked the relay the other day I didn't install it correctly, but having a bad ecu I couldn't tell. 

All well, all better now

What relay does the start position energize? I was testing power in the top fuse panel and the ems relay 1 in the lower left corner, when checking the switch side to ground it energizes a relay in the clutch area. I wasn't sure if that was normal but I'm thinking it's not.

Cuz it does lol

Just now, Mackpro said:

Yes 85 should have 12 volts on it when key turned to start position. But you only have a few seconds to test it. , then you have to cycle the key and try again. 

Should it have 5v key on, not start?

Relay tests good 133 ohm, 86 has 20ohm resistance

So 85 has 5v with key on, 12v in start.

Truck is 012413

Ecm vin is 012416

So this ecm may not work, I depinned 29 on the x2 connector, which is testing as starter relay ecm ground, and the ecm is supplying 3.5v with the key on to this circuit. I don't think I'm supposed to have voltage there.

Thank you

Pin 59 on the harness has resistance, 20ohms, other 2 grounds 0 ohms. Both 57,60 have battery voltage with key on

Which relay actually sends the 12v signal out to the starter relay? 

This is key on, - on battery lug

Yes it does, f38 tests good, 12.5 on one leg no voltage on the other, in going to check the plug on the firewall now

10 hours ago, Mackpro said:

The small chrome auxiliary starter solenoid/relay that’s bolted to starter is where the magic happens. The small red wire pretty much comes from the key switch and starter relay in the fuse box. The black wire goes back to the engine ecm. These two wires are in a loom together and come off the back of the engine harness and over the top of the transmission. Turn key off and let truck power down . The key on and then to start position. You have one 5 second shot to check the voltage on the red wire . Which should be 12volts. After 5 seconds the VECU kills the starter relay voltage. You have to cycle the key back off to re-test. 

Yeah, I've got constant 3.5v with key on on that red wire. I'll have to yank the doghouse to chase the wire any further.

So I think there's a short to power somewhere, key on the starting solenoid + wire has 3.5v on - battery post. Ecm connector + pin to the lug hoop has 0 ohms no other harness connections have any continuity to the hoop. Whatever took out the engine ecu seems to have also killed the abs module, because that's throwing a 254 code now that the ecm is on the can. 

The new ecm is from another truck that's basically exactly the same, ordered for fleet use with consecutive vin#s

So, I've got my data link back after swapping a good ecu. However I'm still not getting power to the starter when turning the key.

Mid 144

Ppid 3

Fmi 3

I can't find anything on this code, I'm stumped.

Pull the fuel supply and return off and run them into a 5gal bucket, full of clean fuel. Fuel rate at idle should be able to be found somewhere. Measure fuel after a predetermined amount of time. You can also try running a new fuel supply line and see if that fixes it. 

Something could be shorted internally in the ecm too, and thats a tough to find without dealer software or swapping ecms

If you use the pins you found in the book that that switch should be wired to and wire it up, then apply constant air pressure through a jumper air line and drive it. Or wire a light bulb in line with the switch and see if it's actuating when it's supposed to. 

How's fuel volume? Just because it's making pressure doesn't mean there isn't a restriction in the fuel lines somewhere, which would strangle the engine in all gears and not produce any smoke. Hard to say that smoke at idle pushing the rack is "good", there's no load in neutral.

I've started chasing datalink/can bus wiring. With everything plugged in pin C reads 2.3 volts, pin D 1.9. When I unplug the engine ECU pin c voltage increases to 2.65v and pin d voltage remains constant. Resistance across can lines is 120ohms. Unplugging various can bus sensors doesn't change voltage at pin C or D, however in getting over 3v at all the sensor connections at the harness on can high wires. Unfortunately I don't have a diagram for the ecu pinout and I can't get into macks ESD right now.

Does it have the right injectors in it? Have you thermal gunned the exhaust ports? Dial indicator the rocker arms to check travel? Bent pushrods? 

Did you tie a light bulb between those two pins to simulate some resistance? Maybe pull that switch and apply air manually and see if that fixes the problem, although it might not be programmed in the ECU to begin with. If you got no boost and no smoke it's definitely pulling fuel, how does it pull in low range? Does it struggle at all? 

Hey everyone, I've got a truck I'm having some trouble with. 2010 cxu613, dash lights up but won't crank. Battery voltage good, relay good, all ignition relays/fuses checked good. Ecm is sending voltage to relay.

However I'm getting a mid 144 pid 200 fmi 9 in the VECU, ECU data "operation failed" truck sat for almost a year cuz of bad injector cups, were about to do a inspection and see if we wanna save it. I've cleaned all the ground on the starter and on the block by the pcv seperator.

No trucks burnt luckily, however we lost a 28' fruehauf dump trailer that was parked under a manure line.

Tm Lost some birds but i don't know how many were in that coop, less than 120,000. For reference there's 2 million birds on this site alone. 

On 2/3/2023 at 2:11 PM, skydawg said:

A farm has a hundred trucks? In Connecticut? 

We've got over 100 registered trucks and trailers, across 6 locations in ct and 1 in maine

On 1/31/2023 at 11:14 AM, bulldogboy said:

Was that where the chicken barn burned the other day?

 

Yes. I left about 20 minutes before it started

So I've been busy with a freightliner all month. Rolled in May? I think. Just got some time and got going.

And did this just start? I personally have no idea how much our trucks consume between services, I only see them when they need major work.