Fried PCM (Lightening strike)

[Dieselnut59]

I posted this in the "911" section also, but wanted to get an opinion from the 3rd generation specific folks too.

I had a lightening strike hit a tree beside where my truck was parked. The lightening ran down the tree and blew out the ground under my truck's rear tires. I think it fried my PCM computer. The engine cranks and runs fine, but none of the gauges work, lights are on in the dash, the headlights come on (and cannot be turned off with the headlight switch), the horn does not work and the overhead console is inoperable. Any suggestions on what to check, what else to check, etc? Where is the PCM located?

Thanks for the help!

John

 

[Matt400]

Sounds more like an instrument cluster fault than the PCM, I would call insurance ASAP and take pictures of the area.

 

[HBarlow]

You're probably correct but I'd try removing the negative leads on both batteries and leave them off for 10 minutes or so then reattach them and see if any of the confusion clears. The PCM may just be temporarily confused.

 

[EDankievitch]

I had a lightning strike near my 02 a few years back when I went to shut down the truck it would not! it kept running with the key out! he wipers kept running also. took a few times turning the key on and off to get it to work right was funny at the time. Strang things happen around lightning... Let us know what you find with your truck.....

 

[Dieselnut59]

Removed the battery cables and let it sit a couple hours but the problem still exists. Performed the "gauge test" function again and all the lights/needles are working during the test. Seems to be no communication from PCM to gauges. Overhead computer is not working and the headlights stay on while the key is on. Engine and its functions work fine. Where is the PCM located? While at it, I want to gut that damn "dinger" thing! Thanks for the help...

 

[DieselFiend]

I'm sure you've already done this but I'd definetly go through all your fuses. It could be something as simple as that. They are there to protect wires and electronics from frying during surges and stuff like this.

 

[Dieselnut59]

The first thing I did was check the fuses. I will double check again, but none were bad. I removed the gauge cluster to check its connections and they appear perfect. Where is this freakin computer? The guy at O'Reiley auto parts said he could test the PCM but I will have to bring it in (of course) and he would let me know if that's the problem.

 

[Matt400]

Where is this freakin computer?

On the side of the engine block, ECM- Engine Control Module.

PCM's are on Gas applications.

 

[Dieselnut59]

Tell me if I am wrong, but I was told there is an ECM (engine control module) AND a PCM (powertrain control module). My buddy's '98 fried the PCM and the gauges, charging system and some accessories would not work. That is the problem with mine. Engine works fine. My understanding is the gauges, some accessories, horn, turn signal clicker, the annoying door chime and automatic transmission (if equipped) run through the PCM.

My ECM is fine. It is the one supplied by Cummins and mounted to the side of the engine. I am thinking my problem is the Dodge-supplied PCM. O-reilley auto parts lists it and said they can test it...

 

[sag2]

Sounds like the BUS is down or one of the modules is taking the BUS down. Before you go throwing money at replacing modules, take it to the dealer and have them run a module scan to see who is still communicating on the BUS. Also don't wait too long to contact your insurance company if it turns out to be expensive. I would find out the extent of the damage before I contacted the insurance co.

The module scan is done with the DRBIII and should take 10-20 minutes, or less than $100. 00.

 

[Dieselnut59]

What is the BUS and where is it located? Where is the PCM located? I have never taken my vehicles to the dealer (or any shop) and do not want to start today if I can avoid it...

Thanks!

 

[Matt400]

On a gas truck the PCM is under the hood where the passenger fender and firewall meet but I doubt you will find one. On early 3rd gens with autos there is a TCM (transmission control module) there. I hope you called your insurance, this stuff is spendy and parts are scarce with what is going on. I need an IMP (integrated power module) a couple weeks ago and they are on back order with no delivery date given or expected.



I would think a good homeowners policy would put you in a loaner while your truck is in the shop, just a thought cuz you may be getting into some heavy expense.

 

[Dieselnut59]

Talked to my insurance company. I have 3 other vehicles so I am not worried about it being down, but I expressed to the insurance company that I prefer to do the work myself, which they had no problem with. Not sure how to work it, but I despise going to a dealership (or any other place) because of the inconvenience of leaving the vehicle there. (30ish min away, I live alone) I was hoping someone here could point me in the right direction of where to start.
Here is a review of what I have done:
Cranked engine and road tested. Engine runs great, BullyDog performs as always No gauges move, has "check engine", "ABS", "air bag", "brake" and "seatbelt" light on (even when belt is buckled) The reason I feel this is PCM instead of ECM is because none of these things have diddly to do with the Cummins part of the application, except check engine light... but the engine is not in "limp home mode".
Checked all fuses and relays
Removed battery cables and let it sit a couple hours, then reconnected (no change)
performed "gauge test"... all gauges working, eliminating a fried gauge cluster
I have looked all over for some sort of module that works these things but have no clue where it would be located. PLEASE help any way any of yall can. I can get the module for $400-800 (depending on plug configuration) from O'reilley Auto parts, but I must FIND the damn thing to remove, have tested and replace if needed. Thanks for any help!

 

[Bob4x4]

On a gas truck the PCM is under the hood where the passenger fender and firewall meet but I doubt you will find one. On early 3rd gens with autos there is a TCM (transmission control module) there. I hope you called your insurance, this stuff is spendy and parts are scarce with what is going on. I need an IMP (integrated power module) a couple weeks ago and they are on back order with no delivery date given or expected.



I would think a good homeowners policy would put you in a loaner while your truck is in the shop, just a thought cuz you may be getting into some heavy expense.

:-laf 03's do indeed have a pcm,it is not called a Tcm

 

[sag2]

The BUS connects all the modules together, kind of like the router in your home network. As I said you are best to have the dealer do a module scan to see who is still active on the BUS before you start guessing with $$$$ parts. Good technicians have fits diagnosing these things, let alone someone with limited knowledge and the proper diagnostic tools.

 

[Matt400]

I was hoping someone here could point me in the right direction of where to start.

To properly diagnose the trouble you need one of these and a good understanding on how to use it other wise you are left with throwing parts at it to see what fixes it which I doubt your insurance is interested in.

Another interesting point to note is that Chrysler provides the modules over the parts counter with no software so you will need to know how to program the bad module or modules using the above tool.



O'reilley Auto parts is mistaken if they told you a PCM was available for your truck because it doesn't have one, sorry.

 

[Matt400]

03's do indeed have a pcm,it is not called a Tcm

maybe my manual is mis printed, Care to point out the page number in the factory manual for one, or are you simply referring the module that early auto trans trucks had?

 

[Dieselnut59]

:-laf 03's do indeed have a pcm,it is not called a Tcm

Then WHERE is the damn thing located???

 

[clinebarger]

MY 03 had two computers one on the left side of the engine the other on the right side of the firewall this is the one that controls all the dodge stuff (trans gauges abs ac etc. )

 

[Dieselnut59]

MY 03 had two computers one on the left side of the engine the other on the right side of the firewall this is the one that controls all the dodge stuff (trans gauges abs ac etc. )

Hummmm... I cant find the thing over there. I will not just throw a new one at it because I will get the auto parts place to test it first. I just REALLY do not want to have to take/leave the truck at the dealer... that is SO much of a hassle!