2021 Ottawa T2 yard truck, Cummins 6.7. Codes 7381, 4276 and 5626 for DEF pump motor speed. I’ve been trying to diagnose this and the thing that is weird to me is KOEO, I have full supply voltage to DEF pump but after about 15 to 20 seconds with key on, supply voltage drops out completely. I was trying to see if there was an issue somewhere in the harness so I unplugged it in multiple points but the strangest thing is when I unplugged the 14 pin connector by the ECM, I still have a voltage dropout, but it drops down to 9V instead of dropping out completely.

My other issue is that in Cummins troubleshooting it tells me to check the DEF dosing unit relay but this truck does not have one. It just has a general DEF power relay and I don’t know if that’s what it’s supposed to be and they just labeled it poorly.

Working with mixed fleets of all sorts of diesels, so looking to hear a wide array of opinions on which software are actually used by their techs... JPRO comes up as the general go-to for most, but is there any options without the subscription fees or a lower cost? Crazy $$$ for these before you even look at the hardware needed!

Working on Cummins/PACCAR/Isuzu/Hino/CAT/DD/Volvo/JD/anything-diesel-under-the-sun , so feel free to chime in with any and all tips on your area of expertise

The company I work for has had no traction convincing tech to go the ASE route so they implemented an OEM driven education plan. I’m soaking up new knowledge but I’m slowly realizing my shop is going to do nothing with it. They’re going to stay stuck in their ways as always. All of this comes with a series of pay increases but there’s no word if we get actual certifications. Obviously just deal with it, take the knowledge and take the money it’s irritating knowing the goal is to better troubleshoot and maintain but nobody is going to pay attention. Is this across the board? Is this whats out there now?

Currently working for Penske as a diesel tech, they’re screwing me with a new schedule change so I applied at Ryder and will most likely take the position.

My question for anyone who knows, The posting stated you had a to have a CDL, I currently do not but was told I’d have six months to acquire one. Is this still a hard requirement and if so, how does the process work for Ryder? I’m in Michigan so I know I have to go through a school but any other details?

If you were only allowed to buy one tool and had to spend your money on it, what would you choose and why?

It could be because it saves time, lasts forever, makes your job easier, or just gives you the best value. I'm curious what everyone's "must-have" tool is.

Title sums it up. I work for a dealership, I focus on newer Mack’s and Volvos both 12v and 24v battery systems. I’m in the market to get a battery tester since the shops one gets busy sometimes but I’m unsure what brands too look into. Any recommendations on a good battery tester I can buy?

Posted a couple weeks ago about a Rosenbauer fire truck that was having communication issues. The job ended up being a bit of a fuck around because my boss was too involved and wouldn’t just let me do my thing without interjecting all the time. Truck would run and drive, but not go over 30-35 mph. Gauges are going crazy, cat eyes on the shifter, and “no data” displayed on the dash. Jpro wouldn’t connect because of the obvious communication issue. Boss says it’s gotta be the Jpro 🤦‍♂️. Gets towed in and the next morning everything is working fine. Jpro now connects and shows lots of codes for communication errors and 1939 issues. Drove it around and it started messing up again. Boss decided that it was likely a TCM without doing any diagnostics at all. I walked away at this point because he wouldn’t listen to anything I was saying. Gets a new TCM, and magically it’s not fixed. He blames Allison for selling us a bad TCM. At this point I tell him to go away and let me do some digging. Started unplugging modules one by one to see what would happen and mostly came up empty handed. Then I moved to unplugging the 1939 Y connectors and things started acting more correct, but with obvious errors for whatever modules were missing. Found the Y connector near the TCM had a ton of water in it and the wires were shorted together. Put a new Y in, made a new cable and everything is happy again. Sorry for the long post and crappy picture.

Found this tire wear on the right steer tire.
There’s no kingpin play.
Any ideas what could be causing this?

We run Terra clean through the engine on one’s sooted up real bad. We don’t let it run through the doc or dpf so this was our solution.

I can’t get the initialization to go through in this brand new VGT Actuator

Got one that’s stumping me. Pro star with x15 and Eaton autoshift. Truck is intermittently stalling out, losing all gauges and and shifter starts flashing while going down the road. Found a ton of communication codes across almost every module, all inactive when it came in. Checked batteries, all ground connections, pulled apart most connectors to look for corrosion and visually inspected harnesses looking for rub spots. No issues there. Happened to hop in the truck and noticed the gauges flickered, if I stand on the step and shake the cab I can get it to act up but will start working again right when you stop. Found out when it’s acting up voltage on can hi and can low both drop to zero volts at the same time. Unplugged cab harnesses to narrow down whether it was in the cab or not. Did not act up with cab disconnected. Hooked everything back up and now it runs just fine. Any ideas where to go from here. Hate to send it out and have it come right back

Air compressor to a permanent vacation. The drier and compressor and exhaust tube were replaced. During the test run I noticed the air drier purges subtly with the exhaust muffler on the discharge port. I don’t see an unloaded valve on the compressor. Is this how this system works by using the discharge port as the unloaded valve?

Pressures built normally and all works, but I haven’t seen a discharge exhaust on a drier before.

Hi all, 

I have a crank/no start condition on a 2009 Peterbilt PB-320. I only have 7-8 volts of output from the ECM to the fuel shutoff actuator. Jumping 12v into the actuator allows the truck to start and run normally.

Included is the wiring diagram for the circuit - my belief is that something is damaged in the ECM, because this wire is a direct run from the 80 pin engine harness connector to the fuel shutoff solenoid, and the only thing that creates the proper voltage for this circuit is the ECM itself. There are fault codes that can be triggered by a voltage above normal or voltage below normal condition, but this ECM isn’t recording a low voltage fault - I believe the cutoff for the fault to be triggered is 6v. 

Additionally, I measured resistance from the eyelet that connects to the shutoff actuator to the pin on the ECM connector (pin 42) and had .5ohms, and also load tested the wire and was able to satisfactorily light up an 1157 incandescent bulb. 

Any thoughts? 

We are working on a 2015 f650 with a wabco hpd system. Codes 2581 fmi 5" brake pressure corcuit 2 current below normal or open circuit". 818 fmi 4. "Master relay voltage below normal or shorted to low source".

I have power and good ground on both of those circuits going into the hpb ecu.. ran a voltage drop on the relay circuit which was .2v (which is good) and ran a voltage drop on both motor circuit which both dropped .5v (assuming thats good). Am I missing something?

System appears to be working properly pumps run within time spec. Accumulators dont leak down.

Looking for some advise on this i dont want to just call it for a hpb unit and be wrong. Thanks

Can these motors draw hard intermitently and cause a voltage code?

Im a 3rd year and have my 4th year and red seal booked but my company doesn't do engine work and our fleet is fairly new so only a couple transmission a year and same with diffs.

Im worried about becoming red seal and having a huge knowledge gap. I have an opportunity to go union and have great benefits but that shop doesn't do any major overhaul so ill be in the same boat, feels like my only choice is go work a dealership or independent shop and learn until I can go where I actually want to go.

Just looking for guidance from anyone who's been in a similar situation

2018 kw with isx scr low efficiency, should I drop decomp tube and inspect railings

Hello all, ive got a cat C7 with a KAL prefix that keeps going into derate. It's throwing a ECU 128 PID164 fault 2 code which points at the IAP sensor. Replaced the IAP sensor. Verified ground is good, verified signal is reaching the ECM properly (no voltage drop) and confirmed a supply of 5V. Ive made sure the ground and power to the ECM are both good. Heui is putting out stable pressure with no erratic changes. Also confirmed the ICP is not stuck by unplugging it, the pressure drops when I do. What could be the issue?

Manager wants me to throw a pump at it but im still leaning towards this being an electrical issue. I dont have a scanner but the IAP sensor is reading 1.5V @ 2,000 psi which according to a forum is correct.

My injection pump is leaking oil there

Anytime I let off of the aux input the thing sounds like it’s grinding. This is the first time Ive worked on a brush cutter, all the guys in the shop say it’s normal but being the nature of the shop I’m in I don’t nessecarilly trust them. Any help would be appreciated thanks