I have gone over every single ground and have done every test in the world on this truck! I am getting the peek-a-boo instrument cluster, it will work,then it won't(No bus) and I am at a loss! I even took the time to remove the ECM and clean all the contacts and scrub the ground points on the block behind it,by the way guys, not a bad idea to do that on high mileage trucks when you change your fuel filter you can get to the ECM really easily and mine had that white build up on it. Anyhow, the codes I get when the dash dies are.......900920921940950999I did the self check on the cluster and ALL the lights work. I also did the PCM connections including the white,square com port at the fuse box. The PCM check with multi-meter checked out good too, not sure where to go with this now:think: Please help! Thanks in advance.

I have never even seen those codes before....they arent listed in my reference sheet I have. Have you found any kind of description on them?JR

How are you pulling the codes? All the codes according to my book should begin with the letter "P" followed by the number "0" and a three digit code, BUT, all I have only go up to P0804.

I have never even seen those codes before....they arent listed in my reference sheet I have. Have you found any kind of description on them? JR

Those are the codes on the instrument cluster when you hold the odometer button down and turn the key on. I am looking here for help on description and how to fix it. The only data line that I have not checked yet is the overhead console. I will check that out tomorrow night. PS. I sometimes get a P1689 code on the scan tool.

Codes on the odometer is done with the key on key off not holding the odomrter button

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1689 is communication between vp and ecm if i remember right. Try swapping horn and fuel system relay

Those are the codes on the instrument cluster when you hold the odometer button down and turn the key on. I am looking here for help on description and how to fix it. The only data line that I have not checked yet is the overhead console. I will check that out tomorrow night. PS. I sometimes get a P1689 code on the scan tool.

1689 is a legitimate code and is a no communication error between the ecm and VP44 like mentioned above. The other codes are not even listed in anything I have which leads me to believe either your pulling the codes up incorrectly or something is really wacky with your ecm. Just to be clear, when the dash goes out everything goes completely out? Do you get a no bus message in the odometer? JR

Codes on the odometer is done with the key on key off not holding the odomrter button

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1689 is communication between vp and ecm if i remember right. Try swapping horn and fuel system relay

No key on , key off, just try it... hold your odometer button in and turn they key on to the run position, it will read CHCK and if you have codes they will be there. If you press it again it will do a full instrument cluster check of all your lights too.

I just tried it with my 02 and all it does is run the cluster diagnostics. Mine only displays the trouble codes with the key on off trick.

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I just tried it with my 02 and all it does is run the cluster diagnostics. Mine only displays the trouble codes with the key on off trick.

You have all these codes. LOOK HERE Looks like the PCM needs cleaning.

Learn something new everyday.JR

Like I said before, we have checked and re-checked every connection and multi tested everything 3x over!:banghead:Is it safe to assume I need a new PCM or can you have them flashed and hope for the best? The truck has almost 400,000 miles on it and it runs like a Banshee even with the no bus code. Any advice is greatly appreciated! All the advice on here has been a tremendous help so far, Thanks guys.

What about the central timer module. It is behind the knee boulster to the left of the steering wheel, seems I read somewhere that the connections get loose or dirty and need cleaning.

Been there, done that. I actually forgot to make sure I plugged them in all the way this weekend and the truck would start for a second and shut off. I am pretty sure the Central Timer is fine. Thanks for the suggestion.

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I guess the next question is, to you out there that are way more educated at this then me, is it time to order the new PCM or can a Dealer flash them? I don't know what is the smart choice and will not hold anybody else responsible for my final decision,just looking for advice. Thanks guys

I'm not sure that a flash will do you any good. It may be worth paying a diagnostic fee and take it into a competent diesel repair shop. They should have a scanner that reads live data. Plug it in, start the truck, and read the live data feed on the scanner. This will tell them what is and isn't communicating and where the source of the problem is. Makes it a lot easier to make a decision on spending several hundred dollars. I went through the same thing with my pcm although the problems your having are different than what I was seeing. It is very difficult to diagnose on your own without the proper equipment which is why I made the decision to take it in and let the pros fix it. Luckily for me my friend which is a transmission rebuilder personally knows the owners of the shop I took it to and he reassured me they knew what they were doing and wouldn't just throw parts at it on my dime. $125 diagnostic fee but they waived it because I let them perform the repairs. Yes I had to pay labor rates which I hate to do but sometimes that is the cheaper route in the long run. If you know of a good shop I would probably take it in and at least let them diagnose it. You can then choose whether or not you want them repairing it. The problem will be finding someone who works on them and knows what they are doing. The average repair shop that wrenches on gas engines 95% of the time is likely going to be as lost as you or I would be.

Is it going to hurt anything if I just drive without gauges for short trips? I have 18 miles to work,1 way all highway, just need a little time to re-coup some cash.

It should not hurt a thing.

Going into the dealer this week to get the diagnostic scan done. I noticed the AC compressor does not cycle, isn't that controlled by the PCM too? On top of all that.... I have team and the smell of anti-freeze coming out of the vents! Guess it's time for the heater box to come out too! The truck sat for a year before I bought it, not to surprised about the heater core.

Going into the dealer this week to get the diagnostic scan done. I noticed the AC compressor does not cycle, isn't that controlled by the PCM too? On top of all that.... I have team and the smell of anti-freeze coming out of the vents! Guess it's time for the heater box to come out too! The truck sat for a year before I bought it, not to surprised about the heater core.

UPDATE I had the truck scanned at the dealer today,$80, and they flashed the PCM and ....BOOYAH, all is normal!:hyper:Gauges all work etc... they did say it could be short lived or it might be fine now. The only code they found was 1687 for the no data to cluster. Hopefully it will be fine,but I have some $ set aside for a new PCM just in case. Thanks for all the helpful info guys!

Good to hear let's hope it stays that way although it does seem too good to be true.... JR now Free

Well, went to go to work and this morning and NO GAUGES! That was short lived, guess the PCM is shot, why would it work yesterday, after the flash, and then overnight just go dead?Ordered a PCM from Auto Computer Exchange today, it should be here tuesday, hopefully that brings this to a close. It was weird cause the gauges came back on today for about a mile then when I started the truck again....DEAD gauges. Oh well, at least I will know what I have till I'm done with this thing!

Well, went to go to work and this morning and NO GAUGES! That was short lived, guess the PCM is shot, why would it work yesterday, after the flash, and then overnight just go dead? Ordered a PCM from Auto Computer Exchange today, it should be here tuesday, hopefully that brings this to a close. It was weird cause the gauges came back on today for about a mile then when I started the truck again....DEAD gauges. Oh well, at least I will know what I have till I'm done with this thing!

UPDATE I put the new PCM in last night from Auto Computer Exchange, still having gauge problems!:banghead: They come on and off and sometimes just the speedo and tach go out then the air bag light comes on. I was told these new PCM's are programmed/plug in play. I don't know what to go after now,let me know what you guys think, I am about at the end of my rope.