PCM Repair | 1st Gen Cummins

[@thrashingcows8610]

I was having the exact same issues you were on my truck recently...eventually determined it was PCM related so swapped in a spare and and that solved all my issues. But now thanks to your vid I'll dive into the OEM PCM and replace those capacitors and see if it gets things working properly again. Thank you so much for the great vid and repair!!

[@SteveLeggans]

I am doing this repair for my neighbor that is having the symptoms mentioned in your "PCM Repair #2" 1 Gen Cummins video. All of the capacitors that I removed were rated for 25 volt. I did determine that the 220 microfarad capacitor (corner of board) that is closest to the 470 microfarad capacitor was bad. With my voltmeter the bad (220) capacitor measured 14 microfarads. The other 2 capacitors measured good (labeled value). I am still going to replace all capacitors with new ones. Thank You for posting this video it was very helpful!!! The microfarad must be the same when repairing electronics, but it is ok to use a capacitor rated for a higher voltage. as long as you have the physical room to place the new capacitor. The capacitor with the higher voltage rating (and same microfarad) usually will be larger. But you should not go the other way and replace a higher voltage rating with a lower voltage rating. The repair may work but the lower voltage rated capacitor could fail sooner than the higher voltage rated capacitor in your repair.

[@Ciulster]

Absolutely brilliant man. I had heard there was potting material in these PCM's but I think you are the first person to actually try remove it to accomplish a repair. Most other people I've seen get that far just give up. The tip about only doing it around the capacitors is definitely a good one too! I am confident this is gonna get my tach working again I'm gonna get those capacitors on order ASAP! Also might be worth noting that the hot side (+) of the ASD relay trigger circuit is either switched ignition power or controlled thru the PCM too (can't remember at the moment where it comes from, but it only comes on when ignition is on run). So as long as the voltage regulators are working in the PCM and you are getting + power to the relay trigger terminal when the ignition is on all you have to do to close the relay is provide a permanent ground to the - side of the trigger relay by cutting the wire and running it to the body or battery. This is what I did just to get the truck to charge, and may be easier than internally grounding the relay in the PCM for most. If I remember correctly red wire is constant + power, blue wire is power out to run everything that needs + power when the truck is running and blue/yellow is the grounding wire that the PCM would normally ground to activate the relay. Forget what the hot trigger wire is, maybe pink? Keep in mind I also have an external voltage regulator installed so I've taken extra steps to eliminate the PCM from the charging system entirely. But hopefully this might help someone else! I'm glad someone finally stepped up to the plate instead of shying away from a computer problem for once. Good job man, really!

[@OvensGarage]

Thanks I really appreciate this comment and the support! I'm thinking this will fix your problem as well. A lot of guys are having issues with their PCM's and this isn't an overly complicated fix. On the ASD relay, I could have grounded out the wire on the truck like you said and it would probably work well for most, but my intention was to keep the truck as is and not mess with the wiring, keeping the repair internal to the PCM so it could be easily swapped between trucks. Appreciate you watching! Cheers.

[@davidcole3927]

The Dreaded Capacitor! Nemesis of many older electronics. I tinker with 📺 tvs, video game systems and Laserdisc players. Capacitors are a necessary evil and die, causing all sorts of problems. Great job man👍keep up the great work.

[@OvensGarage]

Thanks for watching I appreciate the support! Slowly learning more with electronics...I'm no expert but I'm willing to learn.

[@tobylou8]

Great video and it addresses the most common fail of the PCM, a non charging condition. I spent north of $400 to have mine repaired a few years ago. Your solution is certainly worth the effort!

[@OvensGarage]

Thanks, hopefully this solution works for others!

[@darrelldubree9658]

Thank you. I sent mine off through a local reputable garage, cost I think it was $400. I looked at it when returned, and it looks like that is all they changed was those capacitors. Mine started acting up a couple years ago, intermittently. I could hold up on the main wiring harness or tap the side of the pcm and all the charging, tach, and speedo and od would start working again. So you are spot on, thank you, thank you so much. It is crazy what simple and inexpensive things fix what normally people charge a lot to do. Take care :) Enjoy your videos, like the real, non staged product :)

[@OvensGarage]

Glad it helped. Yes you are right, people pay an exorbant amount of money for things that should be free knowledge or open source. That's why I wanted to share it with everyone. I could have easily kept the knowledge to myself and started charging people for it but why would I when I could help out the community. Cheers!

[@Desertmutt7]

The video every single first gen owner has been waiting for! Thank you! I will be happy just to get my speedometer and cruise back

[@OvensGarage]

Thanks for watching!

[@jimkillen1065]

I appreciate the video. While there probably different i have a 95 4x4 automatic.. Many years ago my truck started having all kinds of weird problems. FINALLY i ordered a rebuilt pcm from Dodge or Mopar from a on line discount dealer . All of the folks on the forums said no it some else not the cpm . I installed the pcm and problems were fixed .. Thanks for the video

[@OvensGarage]

Glad it helped!!

[@MTMiser]

You're a brave man, Tyler. That potting material probably would have killed my enthusiasm, but you powered right through it. It's great to see how these things can be fixed. Great job!

[@OvensGarage]

Thanks for the support!

[@JB-pl7ee]

Hi , can I get the specs for the diodes above the 2 capacitors .Mine are fired .@@OvensGarage

[@jonboat9979]

Thanks for making and sharing this video! I have been having issues for over a decade. I ordered the Capacitors today. I will update asap. My truck has all the the issues listed, except my grid heaters works normal. The WTS light stopped working in the last year. I have worked around the charging issue with an external regulator. MY O/D is on a switch. Thanks for the all the videos and Knowledge.

[@OvensGarage]

Good luck! Did it work?

[@phonypony5.0]

This by far the best video on this issue ! You are one smart dude

[@OvensGarage]

Thanks brother! I've got a second repair video that approaches the potting material in a bit easier way if you want to see that pcm repair #2 is what it's called.

[@phonypony5.0]

@@OvensGarage oh man that's great I'll definitely watch it

[@accent110]

Thank you so much for making this video. My truck is gas operated with different issues but your video showed me the process and labor needed to seek fixes to My problems

[@OvensGarage]

Glad it helped!!

[@ThePoofdiggins]

I've have this problem too... pulled the board out and it's visibly burnt, but I'm to cheap to buy a new one😅 so I'm going to test my skills and try to rebuild it!! Wish me luck🤣 thanks for the vid!!

[@OvensGarage]

Good luck!

[@Kyle-iz5qt]

Awesome thank you, my start up procedure has never worked since I've owned my truck.

[@OvensGarage]

Give this a shot and I bet it'll fix your problem!

[@johnnydyck4870]

Wow! I have this same problem and I already replaced the crank sensor (speed sensor) now have the pcm out just didn’t know what to do. I really hope the same thing will fix my truck. Thanks a lot for the video!

[@OvensGarage]

Please report back if it worked when you end up trying this out! I'd love to know if it solves others problems as well! Good luck 👍

[@matthewbrown761]

Did you get around to doing this or not?

[@johnnydyck4870]

@@matthewbrown761 yes I did and it works. This video is extremely helpful and if you watch close and do exactly what ovens garage does you will have everything working if your pcm is the problem.

[@matthewbrown761]

@@johnnydyck4870 awesome, yeah the truck never had Startup procedure since I bought it years ago and I tried trouble shooting the TPS and speed sensor and things like that.. readings on the multimeter were way out of wack but I think this is my solution here

[@davidswier3571]

I have built the fix for this problem. You do not need to remove the pcm. You simply connect the three wires from my new control mod. Into the wire harness on the driver's side fender well. 20min tops solve your problem with out stress and without breaking the bank. Just 3 simple connections. I'll send pictures and instructions with the part. No need to "delete" your PCM

[@OvensGarage]

I'd like to see that.

[@Cabooose20]

Link to this?

[@thinkoutsidethebox4935]

Where is the pictures and instructions? I’d like to see this

[@dotdot9628]

Bro fell asleep

[@decentgarage]

This is incredible and next level stuff man! So cool. Did you test the ASD relay itself. I'm in awe

[@OvensGarage]

Thanks Tim! I didn't test the ASD relay itself but I knew it was the problem since it happened in both trucks. Ended up jumping the two pins at the relay to test it, but the problem was the PCM not allowing the relay to ground, not a problem with the relay in itself.

[@decentgarage]

@@OvensGarage gotcha. You're right it would have been crazy if both had the ASD relay crap out but who knows

[@timpritchett8859]

If you grounded the wire in the harness for pin 51, would it have the same effect?

[@lindajung410]

Excellent troubleshooting and repair! I do have concern that you've full-fielded the alternator permanently by jumpering the relay ground, thus obviating any voltage regulation. This may lead to overcharging the battery on a long trip. But I expect this is no big deal, with perhaps leaving your headlights on 24/7 underway. Most battery issues occur from under charging, not overcharging anyway. Thanks for the video-good job!

[@Littlelewie151]

Its good that you got ALL of that potting compound out. More than likely it was much lighter in color when it was new. It looks like old Sony bond which becomes conducive and corrosive with time.

[@Littlelewie151]

You can sometimes get a resistance reading across it with a meter

[@ZKING25]

Same PCM as my gen1 Viper thx for the vid mate.

[@OvensGarage]

I believe same goes for the jeeps of this Era! Glad it helped.

[@race8427]

Had same issues on my 92 a few yrs back. No charging, No overdrive, No grid heater, No Speedometer. By luck ran into a NAPA parts guy who “knew a guy” that could repair, did same procedure you described. Charged $350 US. With a bit of sleuthing around the PCU before install I determined that indeed he R&R the capacitors.

[@race8427]

PS, a Fluke 87 multimeter among others has a capacitor test function that will indicate capacitance/microfarads so you can compare w/OEM rated. Capacitance can drift/degrade, but still charge and discharge at a lower capacitance before failure.

[@beatymcfierce9436]

Awesome vid dude. Thank god for people like u

[@OvensGarage]

Cheers!

[@cowthedestroyer]

Ive got a gasser d250 right now been looking for ages for a halfway decent w250 cummins but hey why not fill my head with usefull info. Its amazing what people will throw away due to the failure of maybe 20 cents in parts. A soldering iron and the crazy itch to fix something seems to be lost with people just throwing it to the wayside and buying new.

[@OvensGarage]

You are right!..and I want to encourage others to do the same by showing how to do them in videos like these...we need to keep these rigs on the road!

[@letsride2057]

I changed voltage control using a universal mopar external and adjustable voltage regulator and fixed quick, except two made in China defective issues! Third was good.

[@Really-AintBuyn-nit]

There is a work around for everything the PCM does. The AC, the shifting on autos, and the charging system is the easiest. You can sell a working unit after doing the bypass techniques. Or remove the PCM, and put it in a box.

[@bryanevans111]

I put a bridge rectifier in my alternator....fixed my charging problem

[@billg4630]

Its called non conformal coating..take some pics before desoldering it can come in handy later...great vid

[@OvensGarage]

Thanks!

[@daveking6935]

Subbed thanks for this video you're a life saver.

[@OvensGarage]

glad it helped!

[@ronsre-creations5289]

Tyler, Great Very detailed. video ! Hopefully the follow-up video on the donor pcm will net some interesting info.

[@OvensGarage]

Thanks Ron. Still waiting on the guy to send the pcm my way.. unfortunately he's being a bit slow to ship it out. Working on gathering parts for an overhead gauge cluster setup for Ol' Blue for my next project.

[@ronsre-creations5289]

@@OvensGarage I've thought of an over head gauge console as well. I'm real interested in how you set yours up. Look forward to it.

[@mikep95133]

Sounds like good preventive maintenance even if nothing is wrong. After my fusible link fried, my charging voltage at the battery is 14.5v. The gauge reads quite a bit higher too, even with a new fully charged battery. 29 years old and 199k miles, maybe it's time to replace the caps.

[@OvensGarage]

It's cheap insurance! However if it's an over charge situation the internal PCM voltage regulators might need replaced.

[@mikep95133]

@@OvensGarage It's running at 14.3v today. Is that too high ?

[@OvensGarage]

@@mikep95133 I think anything over 14.5volts is too high so you are probably good

[@gusocon319]

Great video, Thanks very much how about a reverse polarity protection diode !

[@OvensGarage]

For the grounding circuit bypass I put in?

[@gusocon319]

@@OvensGarage Yes, sometimes I place a diode To protect the circuit board , Just in case of something goes wrong, your channel and Decent Garage are my 10 best

[@floydrowell3708]

I wish you were closer, Im restoring a 93 d250 with a list of dash/guage issues. But let us know if you open a service fixing pcms.

[@OvensGarage]

I do offer a service to repair pcms at a cost. Send me an e-mail if you are interested. Cheers.

[@wiserswhiskies]

great video are you still rebuilding pcm ?

[@fueldriver27]

Original owner 1993 D 250 12 valve 350,000 miles. Recently on cold start grid heater will not cycle. Stays on to point wires get hot and I can smell insulation cooking. Turn key off and restart works fine. Guessing intake grid heater relay bad. For now I disconnected wires at the heater. Your opinion. Retired on limited budget, want to fix correct first time.

[@Step_Dad68]

Thank you for this video man!

[@OvensGarage]

Glad it was helpful!

[@weldonlee1]

Thanks for the video!

[@OvensGarage]

Thanks for watching! Hope it helped.

[@dougcoval9227]

What does the PIC control and monitor. It's the ic w/sticker on it. How would you read and safe the programming on the PIC?

[@ericfinch9642]

Hello Tyler, I have a charging issue or lack of charging. 12.37 at battery with truck running. My heater grids are working, wait to start, water in fuel lights working. Over drive works as does dash light. AC clutch doesn't engage. I cleaned points of ground on alternator battery and grounds on inner fender & core Support. I have a new alternator ordered to arrive soon. I did try the jumper wire red to green/orange wire. I didn't get a voltage increase. 80,500 original miles on truck. Thanks for any suggestions you may have

[@OvensGarage]

I would imagine it might be related to your alternator then it seems your pcm is still good judging by the other symptoms. Good luck!

[@ericfinch9642]

@@OvensGarage I'll let you know results after installing new alternator. Thank you for your prompt response 👍

[@grb1969]

@@ericfinch9642Did you figure out how to get the alternator working?

[@ericfinch9642]

@George Berven yes, I had a code on dash tell me possible issues. Turns out the crank position sensor was faulty. I replaced it with a New one and all is working as should.

[@Hatya05]

@Ovens Garage Thanks for this video I just did this to my PCM and now my Wait to start light only comes on after I start the truck, it then stays on, at least for the 5 minutes I left it run. Previous to doing this repair I replaced the alternator with a 1 wire alternator because it wasn’t charging. I ran a new wire to the new 1 wire alternator and didn’t use the original alternator wiring at all. I still have the original alternator so I am going to put that back in and see if anything changes. Any other thoughts would be appreciated.

[@OvensGarage]

Yeah I would try out the original alternator and see if that changes anything. Having the wait to start come on after you start the truck is an odd symptom. Unless the grid heaters are on that light shouldn't come on at all

[@ml.2770]

I sense a Mr. Carlson's Lab / Oven's Garage collab on this ECM.

[@OvensGarage]

I've seen a few of his vids..! I wish I knew as much as he does!

[@ml.2770]

@@OvensGarage He is local to you and if you watch his older stuff he likes cars and has done custom ecm stuff to his Firebird. Hit him up.

[@OvensGarage]

@@ml.2770 I just might have to!

[@timenotwaisted3053]

Hey tyler. I have a 1993 cummins auto. I changed the caps in my pcm now everything works except the alt won't charge. I jumped the red wire pin87 with the green/orange stripe pin 30 and still no charge. I took the atl out and had it bench checked at a local shop it tested good. I reinstall it back on the truck is thier any other things i can check where my voltage regulation problems could be. Thanks

[@OvensGarage]

Not sure maybe try taking a look at the wiring between the pcm/relays and the alt, it may have been previously tampered with. Maybe someone put a regulator on it before and it needs rewired.

[@grb1969]

I’m having the same issue where jumping the ASD Relay doesn’t result in a charging voltage higher than the battery’s nominal output. Did you figure it out? 🤔

[@JB-pl7ee]

Did you try the crank position sensor . It fixed my charging@@grb1969

[@timenotwaisted3053]

Best thing to do if everything else works on the truck except for alt just convert it to an old chevy 2 wire set up no external regulators or any other bs problems I did everything in thus kids video and still didn't get the results he got sent it out to a repair facility $250 later they changed all the caps and put in a jump wire it came back over charging @ 18 volts. 40hrs later with a multimeter I've found that my pcm won't internally complete the ground and haven't found a way to rig it so it recognize ground thru pcm. I tried jumping pin 51 and that did nothing for me as well.

[@timenotwaisted3053]

You can wire your your over drive to a 50 psi fuel pressure switch thread it into the passenger side of the trans thiers a plug u have to take out first. Then it will shit on its own at about 48 mph changing fuel pressure sensor to different psi will change when it shifts FYI KZbin has videos of it.

[@charleskuykendall7816]

i was able to replace my capacitors thanks to your video. one was leaking nasty black fluid and I was sure that replacing them would fix my problem, however it didnt. This was the last thing i tried after CPS and testing relays, etc.. did all the recommended checks till it came down to ecm. so what else can I check at this point? ive got no prestart stuff kicking on, no charge, no speedo and my OD light doesnt come on. not sure on ac as its isnt hooked up

[@smallfarm3102]

so i replaced my capacitors, put it back in the truck same issue, not even getting a start sequence or tachometer. took it back out cut it back open retested all the solder joints one tested bad the middle one. it read 0.58 ohms. so i took the capacitor out shot it and its still good. shot the circuit and it reads 0.58 ohms, stuck the capacitor back in but did not solder it back and i shot it and it read 0.58 ohms almost as if its shorting to ground some where in the circuit, im kind of stumped on this one any ideas??? all the solder joints tested good before i put it back in the truck.

[@hippatola1]

Did you ever find the solution for this? We have the same thing. Please Let me know what you did!

[@captiannut]

CAN YOU SEND A LINK FOR THE SCHEMATIC FOR THE PCM PIN ASSINEMENT

[@OvensGarage]

The FSM has the diagram I used in the video. It's available on the 1st gen cummins facebook page in the files tab.

[@v-gang4105]

This is a great video!! Thank you Tyler! My fuel gauge doesn't work, my dash lights are not working and horn is dead. Water in fuel and wait to start work sometimes... I wonder if it's the same issue... maybe just relays?

[@OvensGarage]

Fuel gauge isn't controlled by the pcm its just direct from the gauge cluster to the sending unit in the tank so that's a separate issue. Dash lights (cluster) aren't controlled by pcm either unless you are talking about the check engine light or the wait to start and water in fuel. Horn isn't controlled by pcm. Could be a bad ground (I have a video on that) or a bad horn relay.

[@v-gang4105]

@@OvensGarage Thank you

[@garylewis327]

The message center lights (WTS, WIF, brake, abs, etc.) might just be a bad connection. I have the same issue. There's a round connector on the back side of the message center's circuit board with maybe 7 or 8 pins (didn't actually count them) sticking out that the connector plugs in to. I noticed that if I moved the connector the lights would work. So I pulled the connector off and found that several of the pins were loose on the circuit board. I didn't have time to do a proper fix so just pulled the connector wires off to the side with a zip tie to keep pressure on those pins for a temporary fix. So far that's working, but I need to get in there and fix those pins.

[@outdoormountainman]

Will a standard transmission PCM work in an automatic truck?

[@OvensGarage]

I'm not sure. I haven't tested it!

[@dean3919]

what are the part numbers for the capacitors ? which type do I buy. Panasonic. ? I see diff styles of them. thanks.

[@OvensGarage]

Links are in the description to the Amazon pages that I purchased mine at

[@mustangmike6421]

If you don't put the jumper does it make the check engine light stay on? Thanks for the video by the way it really helped.

[@taylorsowle8209]

How’s your truck been since doing this? Doing mine today. Was having charging issues. Finally eliminated everything and now I’m down to the pcm

[@OvensGarage]

Great so far! 👌

[@donowen3208]

Great video

[@jamesrussell478]

Hey Tyler I’ve got a 1991.5 d250 with 5 speed. Somewhat new to me . And randomly the speedo/ odometer stopped working and also noticed my wait to start light and water in fuel light not turning on. So no grid heater operation. Would you lean to the pcm being the issue? I seem to have good charging and I beleive I have voltage regulator on firewall that’s been replaced as well

[@HobbyBilt]

Do you have a link for your pcm diagram? Having trouble finding that one. Thanks for the great video!

[@OvensGarage]

If you go onto the 1st gen cummins Facebook page the factory service manuals are available in the files tab of that group

[@DavidBrand-p6i]

I have a 91.5 and I am having a overdrive problem. I jumped a wire from pin 55 into the cab and ground it to the door bolt and it went into overdrive on the board what controls that?

[@jobehayes8444]

man i have a 95 dodge dakota 5.2 4x4 with alot of the same issues...i cant find a replacement pcm ANYWHERE and sorta on a time crunch im gonna give this a try only ?? i have is how do you find tje back of the caps?...thanks for the video!!

[@OvensGarage]

What do you mean how do you find the back of the caps? The leads should be fairly distinct from the back side. Good luck hopefully it works!

[@jobehayes8444]

@@OvensGarage 10-4 is there anything that you use to clean the area you were going to solder after you got rid of that gel stuff

[@OvensGarage]

@@jobehayes8444 No I just removed the gel coating as best as I could.

[@ianinskeep7346]

Curious if doing that worked for you. I'm doing the same thing

[@fairbornCCF]

Thanks for posting this video. I only have the voltage regulation problem. Any idea what it would take to actually fix the voltage regulation instead of the bypass method? I like your budget way of checking the capacitors. Strange your capacitors checked good, but just replacing them fixed your issues.

[@OvensGarage]

Is your truck overcharging or not charging at all? I would replace the caps to begin with then go from there.

[@fairbornCCF]

@@OvensGarage It is undercharging. I checked my exciter voltage and it was 12v, so no regulator problem at all. Took off the alternator and took it to Autozone and they said it was undercharging 8v on their bench also. So, simple fix for me. Still wonder if the regulator can be repaired, but that is someone else's problem now.

[@daviddroescher]

​@@fairbornCCF Full bat voltage to fild should = charging. The alt has brushes that wear out. If89-91.5 it has an external regulator on the fire wall. But you show whatever regulator system you have is calling for charge, so should not be a regulator issue. If not the brushes then possible broken fild windings

[@tarzanmario]

hello, great video, helps a lot, i have a 1992 Dodge Ram B250 360 engine, ecm looks just like the one you have here, do you know if this ecm are compatible with different car or truck models?

[@tarzanmario]

8cyl gasoline, also 5.9L

[@1stgengarage]

So I pulled my board out today and it has two heat sinks on it. It has an extra one to the left of where yours is. Any ideas?

[@OvensGarage]

They had a few different versions of the PCM. It's likely a different variant on how the voltage regulation happened on the PCM. The big heat sinks are just to dissipate the heat from the voltage regulation. Is the capacitor layout the same?

[@1stgengarage]

@@OvensGarage I’ll pm you with a picture. The capacitors are in fact in the same place. Everything else is just a bit different. Out of a 1992 w250 5speed

[@timenotwaisted3053]

Do you have a link for the brand capacitor that you used. Thanks

[@OvensGarage]

Links for the products I used in the description. Let me know if they aren't working and I'll fix them!

[@timenotwaisted3053]

Do you have video a on how to wire up a a tach on an auto truck also like the tach setup you have on the red truck was that homemade or can i buy a plastic piece like that thanks

[@OvensGarage]

@@timenotwaisted3053 yep I have a video on me installing that tach in the red truck. Try searching 1st gen cummins tach isspro you should find it

[@dougcoval9227]

How do verify the code is not corrupted or to read that code to programm a new PIC. That's my last step.

[@greatlakescopwatchglcw127]

IIs the tach signal generated solely by the PCM or does the PCM interpret signal from external crank sensor and then to tach. Either way, do you know the tach in/out PCM pin #'s?

[@justinjrowbottom]

The ones you have listed are 25v capacitors but the ones in the ecu are 35V. Was that a mistake in your Amazon link? Or did you run the 25V with no issues?

[@OvensGarage]

Maybe your ecu is different. All the ones I've seen have been 25v

[@justinjrowbottom]

@@OvensGarage odd, it’s a 93 w250. But if you’ve had no issues with 25 then I’ll just replace it with those since I bought them beforehand. Thanks for response, and appreciate all the videos!

[@Lalogoneeebrazzyyy]

@@justinjrowbottom let me know how it goes. mines been replaced with a 35v let me know if they work out good

[@beyondthen4621]

One guy put it into oven at 200 for 30 min. and pulled out perfectly.

[@OvensGarage]

I'd like to see that video!

[@beyondthen4621]

I look for it, he professionally assembled them at factory by his talk. Waited for wife to leave house so she wouldn't nagg.

[@beyondthen4621]

@@OvensGarage Keenan Laws/Engine Computer Repair/Dodge Jtec #1

[@grb1969]

@@OvensGarageLink: kzbin.info/www/bejne/i3y9aJ18p9Glg9U

[@lilrags16]

Was your cruise control not working?

[@OvensGarage]

Yeah my cruise wasn't working

[@lilrags16]

@@OvensGarage was it completely inop or just flakey? I’ve been chasing through my entire truck, and all I can figure is it’s the PCM. I think we’ve chatted about it in the FB group

[@OvensGarage]

@@lilrags16 inoperable when everything else wasn't working too (charging and grid heaters at startup)

[@grahamtassie]

Any chance I can give you a call about one? I’m in the Okanagan and need some assistance. Have it apart currently. Thanks!

[@tigershark1100]

How do I get a copy of the pcm schematic you have? I have the pin in/out from the fsm

[@OvensGarage]

It's also in the FSM but I think it's in the fuel delivery section if I'm not mistaken

[@tigershark1100]

Ok I found it. Once I pause zoomed I saw what it was. You don’t happen to know what the 2 caps together control? One is burnt and so is a diode. My pin 3 is shorted to ground. I want to know if something external causes my pcm issues, or if it’s a pcm issue.

[@OvensGarage]

@@tigershark1100 not certain what the caps control, chrysler didn't release the schematics for the internals of the pcm so you'd have to do some reverse engineering to figure it out

[@tigershark1100]

Ok, thank you for replying. Going to make the ohm meter put in some work.

[@OvensGarage]

@@tigershark1100 good luck!

[@brianparkhurst1820]

Can you help me with my charging problem in my truck?

[@chau8238]

Nice job, I personally got rid of the PCM, but that is awesome. Where did you get the schematics for the PCM?

[@OvensGarage]

The wiring diagram and the input/output schematic is available in the FSM, however detailed schematics of the PCM were never made available by Chrysler.

[@taylorsowle8209]

@@OvensGarage fsm?

[@OvensGarage]

@@taylorsowle8209 Factory Service Manual

[@fullyotto31]

I have a 5.9 magnum. My pcm makes a high pitch noise after shutting the ignition off. The sound continues until i pull the fuel pump fuse. Any ideas what could be making the noise in these things?

[@fullyotto31]

I found that the power inductor is making the sound. I'm not sure why thorough.

[@SLUGEM28]

I got one I need repaired 🙄 wanna try again?

[@OvensGarage]

I'm not opposed to it.. haha.

[@SLUGEM28]

@@OvensGarage well I got one if you wanna enhance your obvious skills lol nice job on it man

[@ethanralphfanaccount6176]

​@@OvensGarage how much are you charging 😅

[@glengraham4395]

Really helpful tx

[@thinkoutsidethebox4935]

Could you just put the ground on the relay wire to a ground in that area. Much easier to access. I’m having a issue with charging circuit only.

[@OvensGarage]

Yep you can also do that

[@thinkoutsidethebox4935]

@@OvensGarage so once that relay was grounded you haven’t had any issue with the pcm regulating the charging? Gonna wire it up in a bit and try it. Was just thinking it may over charge.

[@OvensGarage]

@@thinkoutsidethebox4935 Nope all the ASD relay does is allow the alternator to be activated through the field circuit and the regulation is done internal to the pcm

[@Viktorslife]

Hej Oven. Viktor here from sweden. Sorry for my bad english. I have some crazy problem with my dodge 318 tbi 1989 year modell. I cant get the codes when I do the keydance. It rans like crap after a few minutes and Will backfire and sometimes die when I hit the gas quick. Feels like it ran out of gas. I have change a lot of things like injektors, tps sensor and tempsensor. The car rans "okey" when I drive without the tempsensor connected, but runs like crap when the tempsensor is connected. So I think i must check the pcm like you did. What do you think?

[@JDHamlin-j2l]

I think you should go for it.

[@brandonmiller3786]

I’m dealing with a 1991 5.9 gas no spark thinking it’s the pcm