Need help to ID this transistor

[CapLeaker]

I've got a Cummins Diesel ECM here out of a 90's truck. There is a TO-3 style transistor 828S14 made by MSC in there. It is shorted between the pins. Anyone has a clue what that transistor is / crosses to?

Thanks in advance, guys!

[redwire]

Re: Need help to ID this transistor

What does it drive. Is this for the fuel (rack) solenoid?

[petehall347]

Re: Need help to ID this transistor

allied express have some very expensive ones ..
i searched for data sheet but no luck .. am guessing it will be npn .
shorted between pins is a bit unusual but not unheard of , base emitter are the pins .

[CapLeaker]

Re: Need help to ID this transistor

Here is a picture of it. It's on the bottom board. I took the TO-3 out and the 2 pins are a dead short, which shouldn't be. It may be for the fuel rack solenoid, but I have no schematic to prove it until I get back to the shop tomorrow. The truck doesn't start anymore. First the truck would round an x amount of time and then shut off. After waiting for 2 hrs, it would start again. Now it doesn't start at all. Traced it down to the ECM, opened it up and found that TO-3 shorted.

Those on Ali are no longer available (you have to look closely at the ad). Been there looked at them.

[stj]

Re: Need help to ID this transistor

as you have nothing to lose, see where it connects to.
specifically where does the base-drive come from?
if it looks like it's a normal transistor then stuff in a generic like a 2n3055.

[CapLeaker]

Re: Need help to ID this transistor

I was hoping to use some generic replacement. I'll have a look at the shop tomorrow and see what I can find on their laptops. I'll try some tracing tomorrow, but it is a b*tch at best on that board.

[redwire]

Re: Need help to ID this transistor

The two-pins shorting are a common failure all over the web on Cummins ECM's. This is a 24V vehicle?
It's a custom part and I would guess a MOSFET fuel rack solenoid driver, or +5V reg.
Automotive stuff has to pass load dump/reverse battery connection standards and that sometimes leaves huge oddball parts in an ECM.

This thing is full of TO-220 parts so the TO-3 probably has very low on resistance or has the HV rating for load dump.

I've asked an expert in the business, probably need to know what it connects to.
Will let you know when I hear back.

[redwire]

Re: Need help to ID this transistor

Need to trace out the PCB a bit and see what the transistor does. For the diesel fuel rack solenoid, it could be the PWM switch or boost converter. These solenoids are huge power.

I think it's a MOSFET and nobody really sells those in a TO-3 package anymore unless MIL spec. Modern parts (since 90's) are much better for on-resistance etc. but TO-3P would have to fit.

If the part shorted G-S then check the driver circuit hopefully is OK.
So it looks like reverse-engineering needed to get anywhere with this part.


Chevy's diesel Stanadyne DS4 diesel pump driver module blows up a lot. It uses two parallel MJ15004's 140V 20A ea. hFE=10 lol which get pretty hot and live a short life under the hood. Stanadyne-ds4

[CapLeaker]

Re: Need help to ID this transistor

sorry redwire, I just got back home, but I couldn't make it to the shop today as some thing else came along. So on that picture top left there is that round thing and underneath of it is a rectangular green capacitor. It's rating is 14uF / 150V.
I've tried to trace things a bit but didn't get very far as I loose it, jumping from one side of the board to the other side. One pin of that TO-3 goes straight to the small transformer (next to the two capacitors). The other pin goes to the Motorola IC, splits and goes to a TO-220 as well.
I did take the TO-3 out, measured across the pads on the board and those are shorted too.
At this point I am not sure if that ECM came out of a Dodge, or some International truck, but I am going there tomorrow to find out for sure.

[stj]

Re: Need help to ID this transistor

can we borrow a working one??
one of the cheap component testers would tell what it is instantly.
then we just need to decide on the frequency & current involved.

[petehall347]

Re: Need help to ID this transistor

try reversing your leads when measuring the board . there might be a cap still charged up looking like a short .. i have had this many times .

[CapLeaker]

Re: Need help to ID this transistor

can we borrow a working one??
one of the cheap component testers would tell what it is instantly.
then we just need to decide on the frequency & current involved.

Well, that's something else I am hoping for, when I get to the shop tomorrow.

try reversing your leads when measuring the board . there might be a cap still charged up looking like a short .. i have had this many times .

Nope, dead short on the pads, leads reversed or not, TO-3 removed.

Those TO-220's are IRF540

[petehall347]

Re: Need help to ID this transistor

am just guessing . the t03 being a suspect fet . the gate drive failed and took it out . without a schematic this wont be easy to fix . is there not anyone offering a rebuild service for the module ? being a common thing i suspect there might be .
good luck with it . i know i would be having a hard time with it for sure .

[CapLeaker]

Re: Need help to ID this transistor

am just guessing . the t03 being a suspect fet . the gate drive failed and took it out . without a schematic this wont be easy to fix . is there not anyone offering a rebuild service for the module ? being a common thing i suspect there might be .
good luck with it . i know i would be having a hard time with it for sure .

Yeah, the large disc on top left is a big ass inductor. Looking at the TO-3, it seems to be a fet of some sort, not a voltage regulator. There is almost no way of tracing things in there as it goes from one side to the other and then it ends up being underneath an IC or something else. However I think the short between the 2 pads for the TO-3 is coming from that little transformer next to it.

[redwire]

Re: Need help to ID this transistor

I would say it's part of a high voltage boost-converter for the pump... fuel control actuator. They can be 60-170VDC solenoids.

Is it weird the fat trace connects to TO-3 pin 1, usually the base/gate but goes to TDK transformer. Wondering if this part has reversed pinout.

But anyway, the driver seems shorted too and should be a couple SOT-23's... but if it runs to the MCU then this is not repairable. I think you need more than 5V gate drive unless a logic-level part.

[CapLeaker]

Re: Need help to ID this transistor

Here is an update: It's a big 1994 Ford truck with an M11 Cummins engine. Engine serial # 34765933. It's Actuator connector "C" on that board. Basically there are 8 x 12V supply pins, 3 x return pins and 6 x 2 supply and return pins for 6 injectors. What happens is that there are NO dash lights at all (basically dead) when the ECM is connected, thus wont start. I think the TO-3 is a transistor like an NPN or PNP. I didn't find any other shorted component yet on that board, besides that TO-3.

I checked around, couldn't find a working ECM.

So I did more digging to find the short between the pads. If you look at the back side of the board, there is a wide trace and a small trace where the TO-3 goes. I removed that green SMD resistor on the small trace and guess what? There is still a short over to the other pad!? Wouldn't it maybe be a 3 layer board? With that SMD resistor gone, there shouldn't be any connection to the pad on the small trace and yet somehow them to pads are a dead short. Weird. Nope, nothing connecting them pads on the other side of the board.

[redwire]

Re: Need help to ID this transistor

The mystery TO-3 could be transformer-driven. From that TDK transformer.
That would explain low ohms, even with transistor pulled.

Um, is the TO-3 shorted out of circuit, we know it is pooched?
If not, we may be on a goose chase.
I don't like the black via by the C connector

[CapLeaker]

Re: Need help to ID this transistor

The TO-3 is toast. It's pins are shorted. Post #12. The via isn't black on the connector, the camera just made it look like it. I've poked around there quite a bit.

[redwire]

Re: Need help to ID this transistor

This (fake?) website teases with Cummins Celect ECU schematic but I couldn't download it. To at least find out what the part is.

The big black donut is a potted toroid inductor for the boost-converter.

I wonder if carefully hacksawing the lid off the TO-3 would reveal any die markings?

[stj]

Re: Need help to ID this transistor

russian search engine works well
start here:
http://garageforum.org/Thread-Cummins-Schematics