Identification help

[CraigParton]

I need a little help identifying a transistor. I'm repairing a 2005 Ford Escape powertrain control module that has damaged ignition coil driver transistors. I'm not sure if they are MOSFETs or IGBTs. I believe they are manufactured by ON semiconductor because there's an ON surrounded by a circle in the corner. It is a TO-252 (DPAK) package. I searched for the numbers online and found nothing. Here are the identifying marks as they're layed out on the transistor:

401 ON (ON is circled)

55

03 GM

The circuit controlled is an ignition coil. It rests at 12 volts, gets pulled to ground briefly then turned off to spark. The turnoff produces a decent kickback(usually capped around 60V). Thanks in advance for any insight!

[selldoor]

Re: Identification help

Can you post a picture of it?
Not that I doubt you but we have spent many cumulative hours looking for parts that dont exist relying on what enquirers think they see.
O or 0 or C or D or Q 5 0r S I 0r l or 1 or t 2 or Z M or N and so on.

[CraigParton]

Re: Identification help

Sure no problem. The second pic shows the six transistors I'm replacing outlined in red. I removed the two melted ones already. The blue outlines are two large resistors (.5 - 1 ohm) that I removed because they were badly melted. I was able to find those pretty easily, they were stamped with WSR-2.

[selldoor]

Re: Identification help

Hi I believe it is an LDO voltage regulator or a Mosfet made by ON semiconductors so not much help.
Have not been able to pin down the part number
If no-one comes up with anything perhaps email them - send the picture and ask
http://www.onsemi.com/PowerSolutions/content.do?id=1017

Digikey help desk is sometimes good at finding old part numbers.

EDIT found this ATP401 listed on ON ? branded sanyo
http://www.onsemi.com/PowerSolutions...t.do?id=ATP401

[CraigParton]

Re: Identification help

I believe that might be it! The 100A drain current is plenty for that application and 60V is what I would expect for source to drain voltage. Correct package too. Even if that isn't the exact part I believe it would be an excellent substitute.

I really appreciate your help.. thank you so much! I'll let you know how the repair goes once I get those in.

[Longbow]

Re: Identification help

From a purely electronics perspective, it should be obvious if these parts drive the coil. IGBT's are generally used in this application, and finding suitable devices should not be difficult. Typically these parts would have a proprietary part number stamped on the device, not their usual ID. It is possible, but not likely, that the coil is operated by 6 IGBT's in parallel. Maybe this Ford model has a coil-over type ignition?

Practically speaking, the board is roasted and there is no telling what else has failed. A guess would be that the coil(s) itself is shorted also. I would get the assembly from a junk yard and have a close look at associated wiring as well. Please post results when you get the vehicle running.

[CraigParton]

Re: Identification help

The model does use coil-on-plug ignition. It uses one transistor to drive each coil. By looking at the board I'm assuming the two low ohm resistors are supplying ground to three transistors each, used either for current measurement or current limitation. Regardless they are fried so I'm changing them as well.

I'm also replacing #3 and #4 coils because they are shorted and that's what fried the two transistors. I'm replacing all six as a safety measure. Fords of this model are know for this problem. The reason I'm trying to fix the board is you can't swap PCMs between vehicles without reprogramming and you need dealership equipment for that which we don't have. I'm trying to avoid a trip to the dealer and see if I can repair a somewhat common problem with these vehicles.

I don't think the entire board is fried.. the transistors connect directly to the output pins going to each coil so I'm hoping the control circuits aren't damaged. I guess we'll see. Thanks for the input!

[CraigParton]

Re: Identification help

These are the MOSFETs I ended up ordering. They didn't have any IGBTs in the voltage range I needed. But the ones I ordered were made by ON semiconductor and the voltage and current specs are correct. Fingers crossed.

http://www.digikey.com/product-detai...7-1-ND/2165565

[Longbow]

Re: Identification help

Interesting combination of problems. Too bad this board has to be programmed for a particular model - you would hope that this thing would be a slave board, but I guess it is not.

It seems strange that several of the coils failed, we are assuming simultaneously?

Many 6 cyl. engines with coil-over have 3 coils each driving 2 of the plugs. I could understand one coil failing and taking out 1 of the IGBT's. There must be a hefty replacement coil set that could fit into this application, perhaps MSD makes a good coil-over product. Emitter resistors of low value are a good idea for load balancing if a parallel combination of transistors is used. The controller also has to sense the inductive spike on the primary to confirm that the coil is operating. And so on. Unnecessarily complex? That's my opinion.

[CraigParton]

Re: Identification help

Well I'm sad to say this story doesn't have a happy ending. I replace all six transistors and the two current measuring resistors. I tested the coil triggers with my scope and the four that hadn't shorted worked fine, but the two that were burnt were being pulled to ground constantly. So I'm not sure if the coils shorting damaged the control circuits or the control circuits failed causing the transistors to activate until they burnt out. Kind of a chicken and egg problem I'd love to check, but sadly it doesn't matter because..

You would think that EIGHT screws holding a small circuit board to a cast aluminum housing would be enough. But as the saying goes Ford had a better idea. They GLUED the board under the eight screws making it impossible to access the underside of the board where the control circuits are without breaking it. The melted component were all on top. Well, maybe it's not impossible because companies do remanufacture those but I don't see how they do it. A sad tactic by Ford to prevent people from fixing their PCMs. Anyway we ended up getting a reman unit for it and we're getting it towed to the dealer to relearn the anti-theft password.

I do feel encouraged that the replacement transistors did work on the undamaged coils. Had the control circuits not been damaged I believe the fix would have worked. There was a note in the PCM box saying replacement of all six coils was required for the warranty to be valid. Anyway, thanks for all the info you guys were right on target!

[slackwarerobert]

Re: Identification help

Well now that it is DOA, time to cut open the box to check out the bottom side.

[carTech]

Re: Identification help

Has anyone found a good replacement for these components for the ford ecms

[ricosavy]

Re: Identification help

I have some problem on a 2005 ford escape mine burn same chips and resistors.ordered them from link above.I also noticed the is a a driver chip that i believe controls the circuits the number is 74022pc i don't see any burnt marks how would i check it to make sure it is not bad.here is a picture mosfet and resistors removed.It is 14 pin chip you see in the picture that i think it might be bad also.

[ricosavy]

Re: Identification help

Connected the computer and resistor start to short out what do the resistor connect to

[etech77]

Re: Identification help

ricosavy did you replace all the coils and plugs as well?