1994 1995 GM 6.5L Diesel Salvage Yard PCM Inspections & EPROM Testing & Identification (Chevy & GMC)

[@ryanburbridge]

Your channel is so underrated. I have a feeling your channel will blow up at some point. Keep up the great work.

[@ryanburbridge]

Awesome!!! Always enjoy your 6.5td videos.

[@emso0105]

Fantastic information. I have a 1995 gmc 2500 sle 4x4 ext cab 6.5 diesel and this is a very interesting topic.

[@andrewbeveridge3006]

OMG , YOUR A GENIUS! Thank you for sharing and taking the time to explain! Much appreciated

[@nkdm157]

That’s so much info, thanks !!

[@DanMcD80]

That thing is ANCIENT!!

[@dbrannon79]

DrShock, I have been doing a lot of research on the 94-95 GM 6.5 diesel trucks and PCM tuning. would you by chance be willing to share your spreadsheets on the eproms shown in your video with me? your video actually helped me quite a bit getting started working on tuning and reading the eprom chips. Thank you.

[@samuelshong6959]

Hello and thanks for the information, I have a 95 suburban and l65 engine and bpac broadcast code and I got the bpxy, but I have not tried it on the pcm yet. Anyway, I have read both eproms to compare the programs in them and looks the same to me. I know there are problems in some algorithms. I had to rebuild the engine due to a crack in the block, I got a red good block from 83 6.2l which I rebore.

[@DrShock]

I would be extremely skeptical about there being zero differences between two different broadcast coded EPROMs. The code section could very well be identical, but there will be differences in the data section (e.g., fuel table). GM, always the financially driven automotive manufacturer, would not release and track multiple part numbers that had no differences. ;-)

[@samuelshong6959]

Hi, you are right there are son diferences in the code, I can send you a clone or the program if you whant. Thanks

[@MrDiablolocs]

Hi appreciate all the information you make available for us to enjoy. I have a 94 k2500 6.5 4x4 automatic. I would like to identify if my eprom is correct for the 5521 injection pump on it. The engine is not original installed by previous owner. It runs with lack of power. Just trying to eliminate all possibilities before spending money to have a shop diagnose it.

[@DrShock]

Thanks, there should be a calibration number on the sticker affixed to the top of the EPROM chip. That calibration number will tell you if it's correct of your model year and powertrain options. Usually these will come up on Google, unless it's a more rare or unusual number.

[@SPLavey7751]

Thanks for the video. Besides the fact that the newer boards are obd2 and chip is writable 1 time, what are the other differences between the 97 and the earlier boards? Is wiring harness and pin out the same as 96 and newer? Wish the newer version was configurable. Wish we could implement the Quardstar obd1 live options on the newer models

[@DrShock]

The 1996 and later PCMs for the 6.5L diesel were OBDII and field updatable many times over. So using a Tech2 scan tool and the GM SPS system you could update the calibrations as often as needed. 1995 was the last year for those physical _memcal_ replacement type calibration updates. The wiring harness between the older physical chip swap update PCM and the newer field updatable PCM is different, largely due to the OBDII changes required. But the PCM location behind the glove box area on the C/K trucks remained the same for the whole run.

[@DanMcD80]

On 96+ you can also convert to a 411 pcm origionally used for the ls1 but by being a crossover many of the tunes for the 4.3, 5.7, & 6.5 tunes are readily available and easy to tune yourself for free with tunerproRT or or pay for credits with hptuners which has a more friendly interface

[@SPLavey7751]

@@DrShock thank you for the information

[@SPLavey7751]

@@DanMcD80 Thank you, I didn't know that. Interesting.

[@phillipthomas4489]

The table that you're viewing with the prom IDs and body/option codes that match, is this a publicly available resource? And would it cross-reference with OBDII calibration numbers from GM?

[@DrShock]

No, this is something I put together. These calibrations would not apply, nor correlate, to OBDII being specific to the 94-95 old style plug in EPROMs.

[@phillipthomas4489]

@@DrShock Thanks for the quick response. I have an archive of the OBDII cals and while most of them have a VIN tied to the cal that helps ID its original application, it's not guaranteed to be accurate. For ex: finding references for 16242285.ddc and the other 140 or so cals.

[@brianmetcalfe2754]

Hi I hav a 6.5 in a Winnebago Moter home I’ve bein trying to read the faults in the diagnostics with a wire but the Check light just stops on doesn’t flash at all just wondering if this could be a faulty pcm

[@DrShock]

Unlikely without other driveability symptoms. The PCMs in the diesel C/K truck series are very rugged and rarely fail. Isolated issues are more likely a wiring harness problem (corrosion affecting ground points, for example). I would eliminate those possibilities before looking at a PCM.

[@brianmetcalfe2754]

@@DrShock it has got other symptoms it won’t rev up wen first started just ticks over and white smokes knock ignition off and restart it and it’s fine smoke gone and revs up but Carnot get any codes out of the flash diagnostics any help would be great Iv installed a new pmd got electric fuel pump on a switch and and got the fuel stop solenoid by passed ( removed plunger from inside ) Would u put a copy of the wiring diagram for the pcm on here so I can check the grounds Many thanks

[@DrShock]

I don't have a wiring diagram that can be posted, but the PCM for the 6.5L diesel uses grounds G104 and G105. You can find them shown here - kzbin.info/www/bejne/fmHPfGOKj6qJecU Since this is OBD1 (pre-1996) and you are not able to get any diagnostic response thru the flash code method, I would verify not just the grounds but also the diagnostic harness lines are intact. In my experience, there should be a tall bar before calling a PCM as bad on one of these models.

[@tman8209]

Could you possibly point me in the right direction towards those pages you have printed out? I'm having all sorts of issues with my 94 6.5 with transmission to motor etc total i have 14 codes ans i would hope it's an issue besides the 14 codes.and the grounds look okay. But i would like to check the grounds on the harness going to the pcm itself to completely eliminate that.

[@DrShock]

Those are pages are from the GM factory service manual. It's been out of print for over 20 years now, but they sometimes pop up. There's an eBay search link in the description text for this video.

[@realityro3]

where can i find the pcm diagrams you had in the video

[@DrShock]

Those are sourced from several areas. GM service manuals for the year of the truck, GM service bulletins for the year range of this video, and GM parts information available thru GM service information subscriptions.

[@scarsprospecting]

Do You sell these ? I need a programed chip for a vacuum pump delete etc

[@DrShock]

No, I don't sell anything here just sharing the diagnosis approach. Though there are some links in the video description where you can buy some of what is shown in the video.

[@facundotorres8672]

hi, nice video. I need help my GM silverado PCM was stolen, and I bought a new PCM but it came without the EPROM. And I don't have a file to put it. Would you help me with the file read in the video? would you sell it to me? Sorry for my English, I'm from Argentina.

[@DrShock]

I do not have access to images for these diesel PCM EPROMs. But you could use the broadcast codes/part numbers I showed in the video to figure out which one you need to look for on eBay. If you can't make out the right one, let me know the details about your diesel truck and I'll see what the number is for you. I do not have any information on gasoline engines though, only diesels.

[@ronn2337]

I found that chip in a salvage yard also idk if it’s a hp chip or for torque tho

[@lancalot889]

Is it possible to put the chip in backwards?

[@DrShock]

While within its plastic "Blue" carrier, no. But if removed and you don't take note of the orientation reinserting it, yes.

[@lancalot889]

@@DrShock thankyou

[@JoseLopez-qt7ip]

Can I use 94 pcm in my 95 truck and use my 95 eprom??

[@DrShock]

The 1994 and 1995 EPROM packs were not interchangeable according to GM, so I would take that to mean the PCMs were not either. I would not look at the year as much as the part number on the PCM, keeping it the same as your 1995 one.

[@armenkhanlian3532]

I have a unique situation , 1995 motorhome diesel pusher, 6.5 with 4L80E, just bought her, previous owner had trans rebuilt, changed TCM. When start to drive goes into limp mode! Have to pull over disconnect TCM, reconnect then it shifts fine up and down, till I turn off engine. Then we start all over again, checking with GM dealer have correct TCM (rebuilt by GM) but wrong prom! Correct one is 16252710 for this year. So I bought another TCM same number 16196390 from running truck. Same problem, nothing different . Looks like someone was checking power at the trans, some of the wires have stripped insulation. I’m thinking something maybe wrong electronically in the trans. Your thoughts? We can’t enjoy this RV the way it is. None of the local trans shops either want this 32’ long thing in there shop and mostly they don’t know electronics and something this old. Need your guidance please.

[@DrShock]

The PROM part number they gave you, 16252710, shows in my GM parts book as for a 1995 - 1996 7.4L gasoline engine equipped vehicle's PCM. The TCM part number is correct for a 1995 6.5L diesel though. Can you see what part number your PCM is and what PROM code is on it (using the technique shown in this video to remove the little door so you can read its label)?

[@armenkhanlian3532]

@@DrShock both my TCM have same part number, both are rebuilt by GM per the sticker. the new TCM I bought used from running diesel P30 is 4101BJDM7358 (01427389 B9412AD, the one it came with is BJTW9573 (01427389 B9330, there's also another processor in line with the TCM in a whit housing says LABEL 16188028, not that clear. then QUY 16158945, I don't know much more about the past history besides trans was rebuilt twice, replaced the TCM, why? don't know, notes from previous owner says the TCM thinks its a 6 speed and goes into limp mode. and suggests shifting manually? but that doesn't work well. too much hassle.

[@DrShock]

The 16158945 is a DRAC module (digital ratio adapter controller) which is a early kind of tire size/wheel speed calculator device. What about the actual PCM, the powertrain control module, number? That is the one I was asking about, and the one that will have a PROM module in it as in the video. The limp mode is likely coming from the PCM, not the TCM. I'm not sure where the PCM is located in a mobile home chassis cab type, but it will look exactly like the one in the video as 6.5L diesels all used the same module just different PROMs.

[@armenkhanlian3532]

4101BJDM7358 prom has these numbers also (01427389 B9412AD)

[@armenkhanlian3532]

i heard from someone today they had similar issue with trans going into limp mode and wouldn't shift up unless disconnect and reconnect, and was told it's a ground problem with the TCM and the trans. what are your thoughts on the PCM? haven't located one, wouldn't that just deal with the engine? being a mechanical control diesel?

[@ad4424]

How do you know if yours is bad and you need to replace

[@DrShock]

These chips are pretty rugged, usually you're only replacing them because of wanting the last contents inside them not because of a failure. The contents, the program they hold, was updated frequently to correct problems in the field by GM for drivability or emissions reasons. If the chip were to fail, I would expect to detect that using a Tech2 scan tool as this should cause a failure to communicate properly with the PCM.

[@ad4424]

@@DrShock thanks

[@joshakers1]

@@DrShock I have a 94 gmc k1500 suburban. Im pretty sure the tranny is stuck in second gear. No power at all. Ive checked everything else and replaced about $3k in parts with little to no results. Im down to the ecu and/or shift solenoids. If I go the ecu route I was told I should replace the prom as well. Should I? And if so where can I find one and how do I know if its any good if I go to a junk yard for instance? Please help! I need my horses back!

[@DrShock]

@@joshakers1 Given your situation and spend so far, I would *not* recommend a salvage yard unit but rather just purchase a remanufactured PCM. A remanufactured PCM has been tested to be sure of no faults. Typically the remanufactured PCM you would receive will not have a PROM installed. This is because while the PCM covers many GM models, the PROMs are very vehicle options specific. So these companies selling remanufactured PCMs often just have you transfer your PROM into the replacement PCM. It would be extremely uncommon for the PROM itself to have a problem, so I would _not_ recommend just replacing it for no reason. However, I would strongly recommend upgrading it, if your broadcast code is older. Like I show in the video, in those days before flash programming, to get bugs in the GM code fixed you had to get a new PROM with that new code and physically replace it. So take a view in the video for your PROMs code, and see if there is a newer one. You can find those on eBay at the link in the description, though they can be rare depending on the code you need. There's also a link for a genuine GM ACDelco reman PCM part number 88963802.

[@jcanfixall1585]

Moates is closed down, I'm no expert but there's another company I saw online yesterday that sells the same type of products...

[@paularchambault9515]

I'm curious about using a 1997 chip from the increased hp and torque in a 1994 cpu.

[@DrShock]

1996 and up PCMs are a different circuit board design without an EPROM. Instead they use flash memory, and are programmed using the GM Tech2 scan tool in the vehicle.

[@mtebaldi1]

GU6 Axle Rear 3.42

[@ronn2337]

I thought u we’re gonna talk about the blue chip

[@DrShock]

I did. That _BLUE_ logo is just a brand name for the EEPROM chip carrier. I pulled that chip out of the carrier and read it on the chip reader during the video, and walked thru the memory layout inside it. You might want to rewatch at 11:44 on to the end where I go thru all the details about the chip itself inside that blue plastic carrier.

[@ronn2337]

I found this on Heath

[@ronn2337]

@@DrShock what dose the blur chip actually do?

[@DrShock]

Well the blue part is just a plastic carrier. The chip inside of it, well that's the programming for the powertrain control module (PCM). It's just like any other microcomputer with memory, storage, and inputs and outputs. All of the engine operational parameters, for example, around fuel and air to minimize emissions and maximize fuel economy. Monitoring the transmission, air conditioning, and security systems and controlling these other modules. All of that is part of the PCM programming.

[@ronn2337]

How can I tell the one I found in a junkyard is a performance chip or factory?

[@ishtiaqali1808]

I want to learn the coding, please help me how can I learn

[@andrewbeveridge3006]

Whauh whauh,whauh,whauh, whaouh...😮 sounds like Charlie brown's teacher! No idea she's going on here!

[@ishtiaqali1808]

Hello