PCM Repair #2 | 1st Gen Cummins

[@billg4630]

I just did this to 1993 dodge b350 full size van..worked like a charm..it took 2-25v 220uf capacitors and one. 35v 470uf capacitor..i couldn't be happier..this is a sportsmobile conversion van with penthouse top and all the goodies inside I'm retired and wife and I love the van

[@OvensGarage]

Awesome to hear that it works for those vehicles as well!!

[@jrocksnittos]

Long time viewer/subscriber but the first time making a comment on here. Thank you so much for all you do for the first gen community. Your videos have saved my butt a couple of times, but this one did for sure I have a black, 93 le 4 x 4 auto truck and a 93 red and white le four-wheel-drive, five speed truck that you’ve single-handedly kept on the road lol 👍

[@matthewrice1069]

Thanks for the tutorial. Just completed on my 1993 W350. Problem solved. Took only 4hrs to fix. Capacitors where the correct type as well. Cheers

[@jimkillen1065]

Great job really nice work. My second gen pcm a 95 with the single connector in the pcm a few years ago did all kinds of weird stuff . Finally i gave up and got a rebuild pcm from mopar . Fixed everything except the dropping out of cruise . That was the brake switch. ..Thanks for the video

[@danielmoniz3163]

Nice job! You make it look easy the 2nd time around

[@OvensGarage]

Learning lessons the more times I do it!

[@truckericksdashcam169]

Im saving this video for future reference cause the only problems I had with my 1st gen are , dead short to ground in power feed to trans , fried ignition switch and i had to clean up the main disconnect plug on the battery cable coming out of the alternator.

[@ryantopping235]

Love the First GEN videos 👍

[@OvensGarage]

Thanks Ryan!

[@mrbmcp]

My 92 First Gen is suffering the same issues that you show here! I had a local electronic shop change the capacitors. The one by itself was obviously burnt. The PCM is now in the hands of a local garage. I am hopeful this was the issue!!

[@OvensGarage]

Good luck hopefully that solves your issue!

[@mrbmcp]

@@OvensGarage I had my capacitors changed in my PCM however it did not solve my no charge/grid heater problem! Just spent a $1000 on labour at a Chrysler Dealership and they couldnt find the problem! Do you know any experts on the Island who could look at my truck? Thanks!

[@OvensGarage]

@Mr B I'm about the closest "expert" you'll find on the island, among some of my other friends here. Where are you located?

[@mrbmcp]

@@OvensGarage Qualicum Beach

[@mrbmcp]

Now my radio is out and my dome light and under dash light??

[@mikep95133]

Hi Tyler. I think this is your best technique for replacing the caps so far !! So much easier!! My '93 has 193k miles. No ecu issues that you describe so far. After I weld up the lower door hinge damage, I think replacing the caps on the ecu is good preventive maintenance.

[@OvensGarage]

It wouldn't hurt to do them as preventative maintenance! They are bound to start going bad eventually. Maybe it's a colder climate issue..but good to do either way.

[@mikep95133]

@@OvensGarage Caps die with age and heat. This 1st gen has been in desert conditions it's whole life. Caps are on my to do list !!

[@OvensGarage]

@@mikep95133 Did you ever figure out your fusible link issue?

[@mikep95133]

@@OvensGarage Nope. Drives perfect every day ! That makes me crazy !!

[@idaholineman5788]

Badass video. I need to get into mine and attempt to fix it properly. I’ve bypassed my computer mostly..OD ground switch, grid heaters on a momentary switch. But it would be nice to have it run though it’s warmup cycle in the winter time instead of me having to keep hitting the momentary switch.

[@faronf2006]

Great video but personally I would have used clear silicone to be able to see any bad replaced capacitors in the future

[@ifyounoticethisnamethenyou4717]

Gonna try this on my 90' ramcharger. Way better than buying a new external voltage regulator i think.

[@NathanMorris-m2k]

In minute 7:44 the old capacitor show 35v but verbally and on the link to replacement capacitor says 25v?

[@jimmungai1938]

I had my truck worked on at the shop I had a shop off my way he’s over by Atlantic PA and they messed up my charging system and things like that did all kind of stuff screwed my truck up I find out the guy don’t like first Jen Dodge‘s he should just told me that from the beginning anyhow they had to which is being fair to him he had to modify my throttle linkage bracket because where the cables go in because one of the Hamilton cams had didn’t have a provision for a fuel filter so he had to put a filter from the second GEN on there which is cool I appreciate that but they must’ve re-welded that thing on the truck without disconnecting the battery because that’s why am I’m guessing that’s why my charging system ain’t working right I’m overcharging and things like that you know he really screwed me up bad but I learned something you were talking about that heatsink was what controls how much it charges anyway thanks for the information guy this is six in a row jim From Kennerdell Pennsylvania

[@matthewwilliams2328]

Started my journey on my pcm. The capacitor top left was burnt and fell out when I removed the jelly. I hope that's all that's wrong with mine. The original was fried by lightning. I'm working on my used second hand pcm now

[@OvensGarage]

Hopefully this video helps you in your journey of fixing your pcm. Keep me posted! Good luck!

[@ronsre-creations5289]

Another Great follow-up tutorial ! 👍

[@OvensGarage]

Thanks Ron!

[@Halffast719]

Question time 🙋. So I replaced capacitors in the ecm Panasonic and I’m very good with soldering so everything is good. Plug ecm in and truck will go 10 miles then the A/C, Tach and Voltage drops. So I pulled it back out and soldered the jumper wire like you did and same thing. Drive it and everything is working about 10 miles down the road everything shuts off again. I checked all the pins and even flared them open to make sure they’re contacting. What do you think? It’s my son’s daily driver.

[@OvensGarage]

That's interesting. I'm not sure what that could be. If you have a good pcm it might be worth trying to swap it. Sorry the capacitor replacement didn't fix it!

[@Halffast719]

@@OvensGarage so it turns out my multimeter was trash so I got a new one and checked ohms on everything and the crank sensor was the culprit. Thanks for responding. Everything is good for now anyway.

[@bcbloc02]

Good fix! Have you run into the crazy speedometer issue? Mine will read random mph all over the place it always counts the mileage right though regardless of what the needle does.

[@OvensGarage]

Yeah I had that issue previously on my red truck. The speedo issue ended up being a bad VSS down at my transfer case.

[@SteveLeggans]

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. I am doing this repair for my neighbor that is having the symptoms mentioned in this video. All of the capacitors that I removed were rated for 25 volt. I did determine that the 220 microfarad capacitor 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!!!

[@SteveLeggans]

Completed the repair today (replaced all 3 capacitors) and installed pcm back into his truck. Everything is back to working as it should during cold start up test drive with outside temperatures at 22F. (Grid heaters, overdrive and etc.)

[@ttenrabyrral1]

I hope you may be able to answer a question about the 92 cummins speedometer. Does the PCM (engine control module) provide a signal to the speedometer or should the speedometer work independently from the PCM? My speedometer is not working and the auto transmission will not shift into overdrive. The VSS tests good and I've replaced it with another known good VSS, I've checked continuity between the VSS and the PCM and it's all good. Thanks

[@OvensGarage]

Hi Larry from my experience and looking at the FSM the speedo operates independently from the pcm. I believe it still uses a signal from the vss to determine when the truck is allowed to go in and out of overdrive though based on speed. The other thing to consider is the throttle position sensor and it's correct adjustment. If it's out of adjustment (on the top of the ve pump throttle) it can also prevent the truck from shifting into overdrive. Decent garage has a good video on how to check and adjust the tps.

[@ttenrabyrral1]

@@OvensGarage Thank You Kindly for the rapid reply and thanks for the TPS adjustment tip. I will check and adjust that today. I had come to the same conclusion about the speedometer operating independently based on the wiring schematics I just wondered if you may be able to verify. My 1989 is so simple I'm old school been wrenching for fifty years and I greatly admire the automotive engineers of old who were somehow able to make things go without a computer!

[@billg4630]

Love the vid...i have 1993 5.9 gas van my com has good powers comming in and good chassis grnds at computer when back probed...have good 5v &8v sensor output are well..however no ground at pin 51...any input would be appreaciated

[@OvensGarage]

Do those vans have similar computers?

[@PebbleHill-tw4dx]

Would this be a similar process for a second gen? My tach reads 0, a/c doesn’t work, constant gear hunting, all dash lights flicker on and off and the charging system works occasionally. I’ve replaced ess twice, checked, double and tripled checked all wiring and grounds and believe I have narrowed it down to the pcm

[@OvensGarage]

I'm not sure about second gens I'm pretty sure that the pcms are quite different

[@PebbleHill-tw4dx]

Dang it

[@whitevanman8703]

10:48 Is that a 2nd gen steering wheel?

[@OvensGarage]

Nope. 1st gen LE steering wheel.

[@BabyJesus440]

None of my lights work on the info center, truck starts and everything seems to work except the grid heaters. You think this fix will solve that issue? Also speedo doesn't work and headlights have a light flicker to them

[@OvensGarage]

If the grid heaters don't cycle on in the cold and after you start the truck it doesn't start charging, I would suspect PCM issues. Speedo doesn't go through PCM, that's likely a VSS issue, and headlights dim when the grid heaters cycle.

[@dankriewald4764]

Wow , Very cool

[@ryantopping235]

I have a first GEN question for you When I turn my key on my wait to start late doesn’t blink just stays on and then when my truck is running it just continues to blink I don’t have a PCM It’s my first first GEN dodge build I watch all your videos

[@OvensGarage]

What year is your truck? Sounds like the PCM failure symtom for sure.

[@ryantopping235]

@@OvensGarage it’s a 1990 W 250 no PCM in the truck

[@OvensGarage]

@@ryantopping235 I'm not familiar with the 90s unfortunately! Not sure how they operate the grids. I think there is a module under the hood somewhere.

[@ryantopping235]

@@OvensGarage The one downside of the 1990 no computers of any kind and not a lot of people have information on them been learning as I go. Just installed my gauges above my rearview mirror like you did. Looks awesome

[@OvensGarage]

@@ryantopping235 that's great would love to see what they look like

[@alsun35]

i plan on selling my g360 here within a month once my new trans is rebuilt, im only 12 hours east. Needs a rebuild but if hes interested. These arent the same trucks auto vs manual, im sure you know that owning both lol.

[@OvensGarage]

I'll let him know!

[@roughcutsgarage]

Hey, thanks for the offer but I won't be in a position to rebuild and swap for a while. Love your vids of the truck btw.

[@telfordparks6083]

Hey, I know this is an old video but if I have my brake light light on, abs and water in fuel light and my brake lights don’t work after my alternator was over charging the battery/system would this be the pcm at fault or do I have to chase everything now?

[@OvensGarage]

@telfordparks6083 your brake lights coming on or off shouldn't have anything to do with the pcm

[@telfordparks6083]

@@OvensGarage ok thanks but what about all the dummy lights like the abs/fuel in water?

[@johnmatarazzo1901]

1st gen life

[@OvensGarage]

Classic

[@leonardford6815]

I got a 1992 LE dodge cummins. I want to restore it. Bought brand new back in 91. I had a business where I used it for business. Bad part is I had 8 different guys driving it. It came with cruise control. The speedometer don't work.And the streering wheel is rough . [needs switches] I have a 1991 parts truck that has a working speedometer but no cruise control. Are the PCM's worth swapping ?

[@OvensGarage]

Is it showing signs of a bad pcm? No need to swap pcm if it's still working.

[@leonardford6815]

@@OvensGarage thanks thought that effected the speedometer as well ?

[@gummyvalenzuela2509]

Question., which one is the overdrive calacitor?

[@OvensGarage]

I'm not sure, but if you are in there I would replace all of them.

[@gummyvalenzuela2509]

@@OvensGarage thank you sir

[@fredcook1845]

I have a 92 with the auto in it can l put a pcm out of a 93 with a 5 speed in it. Are the pcm's the same?

[@fredcook1845]

Help

[@ram_diesel_power6039]

Low fuel light. I never noticed one. Most fuel I’ve put in is 29 gallons. Oops 😹

[@OvensGarage]

Haha, yeah his fuel gauge is malfunctioning. We had dropped the tank the day before and I don't think we plugged the sensor back in correctly. Way to test it is probably just unplug the sensor at the tank.

[@idontuploadjustwatch]

Got a question for you. I’ve been chasing cruise control problems in my 93 5 speed. So far I’ve replaced the clockspring, cruise servo, and tested vacuum. My odometer, ac(bad clutch), dash/info lights, grid heater, speedo,charging , and tach all work. I was looking into doing a quick pcm/ harness continuity test next to narrow this down. But for the life of me cannot get cruise control to work, would one of these capacitors come into play with that or not? Any tips would be much appreciated

[@OvensGarage]

I don't suspect that the PCM would be the problem causing your issue. I would take a look at the wiring diagrams for the cruise control to start so you can rule things out. I have not had any issues with cruise control on my red truck so I can't really give too much advice. One thing that came to mind though and not sure how you could test it, but when you depress your brake pedal the cruise control disengages. If there's a way to jump that switch (probably the brake pedal switch), I'd try and rule that out too. Otherwise, maybe the clutch neutral safety switch has something to do with it would be my next guess. I doubt something is wrong with the cruise itself, it's probably just something from preventing it engaging and staying engaged.

[@idontuploadjustwatch]

@@OvensGarage I’ll check into the clutch safety as I’ve already tested the brake switch. I would imagine some issues with my repinning job on the new servo…. But I’d have to rack my brain with some wiring diagrams on the clutch safety as it works properly as far as I know…

[@OvensGarage]

@@idontuploadjustwatch Was just looking in the FSM, did you see the section on "Speed Control System - Test Procedures"? It is group 8H-7. It runs through a couple testing methods to rule out the servo and PCM it looks like.

[@idontuploadjustwatch]

@@OvensGarage speaking of, with your working cruise control, is there a minimum speed that it will activate at?

[@OvensGarage]

@@idontuploadjustwatch yes. I believe it's something like 50kmh. It's in the FSM I'll have to check.

[@keyanjones3620]

What was that buzzing noise

[@OvensGarage]

You may be referring to the grid heaters? They cycle on in the cold weather.

[@johnmatarazzo1901]

Mine won't charge I am forced to sell it now