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RAS041

Hello, new O/O (will be upgrading to tractor ASAP) with plenty of tech. background making the jump to diesel. Working on my truck I effectively cleared all dtc except a barometric pressure out of range, intermittent, or erratic.

I recalibrated the ecm, thinking it somehow was reading wrong. it was the same calibration dt90275.15 that was in the truck. this is when the extra fault codes came on. just recalibrated ecm and the faults appeared. my def gauge that was working and full now has a light on and is at empty. just malfunctioning, the def temp sensor, fuel level sensor, and starter relay circuit are all throwing these Cricut above normal or shorted to high source as well as the barometric pressure data erratic, intermittent, or incorrect that started this whole thing.

I suspect the mechanic I sent the truck to may have changed some parameters to address the def faults they are almost identical and the man told me he needs a ton of cash to replace my turbocharger that was fine, but needed an actuator that I put in. Maybe my recalibration uncovered the root cause of the skewed barometric reading?. It is steady at that same 14-17 hg value.

Also, my sensors are getting about 7v. Is that going to skew my readings and return voltage, being that they are 5v circuits?. The sensor signal for Baro is .75v, a little high?.

I tested everything vs the map sensor. I actually bought twice to be sure, as I believe the Baro read is before I turn over engine at key on, then it reads intake/boost??. The reading was 14-17 hg which it should be closer to 30 if I'm not mistaken so I assumed it was out of range.

I refurbished my grounds. The battery neg. ground is (3) batteries in parallel. The ground on the frame rail is a post welded to the frame from factory. It has holes between welds and is rusty and crusty although I just hit it with the wire wheel last month. The nut and bolt have surface rust. Shouldn't it be good if it is tight and clean at connection?. I get 0.15ohms at that ground (not cranking).

I am getting voltage spikes up to 38v but they seem very fast and superficial, but the volts are all over between a couple volts and the 38v. The main power cables going to starter then alternator is stable at 12.5 keyed off but there's this four post, large 12v solenoid attached right under the windshield in engine bay with two thick positives cables and then two thinner 10-14 gauge wires. when they are attached, the large wire coming from behind the back of the block, not the alternator is the one that's spiking, as well as one of the smaller wires attached to it.

That's as far as iv traced it so far. When I disconnect the four wires, the truck still starts and the one large power wire is still spiking. So (I'm trying to figure out what feeds that hot wire) the smaller wire that was spiking is not spiking.

I notice at startup the voltage on dash in cab is jumpy between 11.5 and 14.1v. then settles at 14. the regulator in alternator is good. unit is brand new. I'm going to keep tracing the spikes. it has to be a bad ground, ground wire, or connector or a short in the positive cable.

Batteries are new and stable. Bad Bulkhead Module,? ECM?, ... what regulates the voltage besides alternator?.

I believe the solenoid allows the recharge volts into the battery bank maybe. It does charge but could a short cause overcharging and back feeding?. I can't stand electrical work.

I'm going to continue tracing it. I have replaced starter, alternator, batteries, trans cool lines, Fuel rail press sensor, Nox inlet sensor, Map sensor, coolant temp sensor, I put a new pigtail on new map sensor, replaced ecm ground strap to engine block, added a redundant ground from block to frame, put wiring back to stock as some sensor return lines were cut, and grounded to ac compressor, which was weird.

Thoughts?, Suggestions?.

Seems to be one underlying problem triggering all of this. My authority has been active a few months and I haven't moved a single load.

Between shady sellers, fake parts, scamming mechanics, parts dealers selling me parts according to my vin and not taking them back when they don't fit or work and having to become my own mechanic, I'm cooked at this point. LOL.

Is there a workaround since a lot of the faults are for inconsequential stuff like tank levels and temp of def tank? A potentiometer on the return signals to bring in range? a voltage regulator? I still must find the source before considering that crap. I don't want to. I must be able to run and earn. you could imagine all the tools, truck, parts, mechanic, and then cost of living I am being pushed in the direction of a work around temporarily. this has been going on for months. granted, much has been repaired. and i didn't know much about diesel trucks.

Rawze

Sounds like someone chasing their own tail and making a mess of things to me.

what is the engine ser#?
What is the vin# of the vehicle?

Is the engine and its ecm original?... or is either (or both) a replacement?.

maybe some history.. like when these issues started, etc?.

RAS041

3ALACWDT4HDJB7232

58693882

Cm2350A

P/n 4358814 s/n 6060544

Thank you!!

I just got Cal term, but I am still setting it up. I have to purchase the files that decode all of the information so to speak. I’m not sure if it’s a calibration thing or a Root issue that was covered up by the shady mechanic I was using thanks again.

Dt90725.06 origional calibration on ecm sticker.
Dt90275.15 now truck already had it

RAS041

Sorry I was working. Yeah the truck was a mess when i bought. Data link was down. No insite. Looked pretty good. Scanner cane up 6891 bulkhead that was it. Once I learned a little i realized the thing was run to derate and thats what saved it. Spit shined and sold. Minimal blowby. Engine and trans are good to go. 280k paid 20k. All genuine parts once I learned aftermarket is crap. And oem on ebay or amazon means from china. Mechanic only got a couple grand out of me. That little turbo 9k to replace? Only needed actuator. Vgt smooth not much resistance when i swing the pizza gear. Im sure i sound like a dipstick. I had cleared a ton of issues down to the barometric reading out of range erratic or intermitant.That was it until I reflashed. I would say its out of range. Needed alot of care. Some of the sensors were probably not needed but wiring that got repaired after I started throwing parts at it and it didnt fix the dtc’s. The recal brought up all the high voltage or out of range. Idk whats up with the baro reading. Why would the codes come up after a recal. Same exact calibration the truck had. Some say parameters, i believe its an electric fault. I want to just look at the parameters and compare to what the sensors are reporting to get more information. You are extremely knowlegable. Would love your honest opinion. I know enough not to put a band aid on a broken bone so to speak. Ill take my licks and learn what Iv got to. Been going on for two months was in shop and glad I towed it home. So yep. Close but no cigar. When I only had that barometric code ran Highway speeds no problem did have some weight in back. Nothing crazy everything ran fine. I just didn’t like the fact that if the barometric stays out of range eventually, it could trigger a.Derate. Ill shut up now.

tree98

You say you don't have insite or c a l t e r m software so you have no way of knowing what program was actually in the ECM before you flashed it with that DT90275.15, just because the sticker says that's the program thats in it doesn't mean anything at all. For all you know someone took that ECM off a different engine and then flashed it with the correct program for your engine...... whatever that might be.

This is a good example of why you need to always back up the program with c a l t e r m before you re flash and erase everything you had.

You need to find out what program is supposed to be in it according to the VIN, sometimes quickserve.com works for that. If not then call the dealer. While your at it verify that you have the correct engine and aftertreatment system for that truck. Who knows what kind of mismatched parts you could be fighting against.

windowrattler

DT90275 is what cummins shows by VIN when I look it up on quickserve.

tree98

And how do you know what program is in the ECM right now?? You don't have the software to flash it so someone else must have done it for you. How do you know exactly what they flashed in ??

Rawze

Vehicle = 2017 Freightliner M2

According to the VIN# and the engine ser#, it is supposed to have program DT90275 in it, so the program is not the issue unless its corrupt, or some idiot did not make a backup of the ecm template before updating it.

Even with the ecm template missing, if it is the correct program for the ecm (and in this case it seems to be), this does not account for engine sensor faults. Faults that are typically seen when the vehicle template is missing are cruise control, engine brake, maybe fuel pedal, but not any engine sensors.

Updating the software will not cause sensor issues like you are describing either ... so either you have bad sensor(s), or some wiring problems somewhere .. or a fried/damaged ecm.

What are the exact faults showing in Insite, and not some trash third-party device codes?.

BTW: All the sensors run on 5 volts. Register the engine ser# on quickserv.com and get access to the ecm wiring diagram .. ensure things are hooked up properly, have the right voltages, etc. and that some moron has not crossed some wires somewhere.