Instrument Cluster

bassman

Member
Mar 5, 2015
9
Sorry because of the length but I have searched for answers and maybe can answer some questions for others and find some for me.

First the problems.
1. I lost speedometer and fuel gauge.
2. Vehicle would not start without trying several times. Fuses were OK. Starter OK. Battery good.
3. At times, all gauges went off and all instrument lights would come on. At the same time, windows, Door locks, and radio quit working.

Steps to repair.
I removed the instrument panel and replaced all the stepper motors. This correct problem #1.
Still had the problem with #2 and #3,, so I checked all fuses and relays. The problem would come and go at steady times like an automatic breaker tripping from an overload and them re-setting. I also noticed that when a bump was hit, it would go off and then come back on when I hit another bump. While standing outside the vehicle, I leaned in to look at the instruments and applied weight on the seat and everything started working. I hit the seat with my hand and everything went off. Each time the seat was hit, the condition changed. My solution was this. There are 2 electrical plugs on the front of the seat. One is the power including data line and the other is the yellow air bag plug. I unplugged the seat plug only and everything started working. This indicated to me that the problem was in the seat. How did that effect the instruments? I think that it was killing the data line either by short or open connection. I ohmed all wires from connection to connection. Everything checked good. I removed the seat Module and since it is only snapped together, I opened it up. There is 4 plugs on the module. One of the plugs has 2 power inputs, a ground and a data line. I found a line around 1 power and the ground prong on the circuit board. I re-soldered the prongs and replaced and re-plugged everything. Now all the original problems are repaired.

Now the new problem. Sometime during all the checks and looking for the solutions, the DIC quit working. The Instrument panel is getting the signals from the stearing wheel switches but I can't locate any schematic's on the instrument board. Can anybody point me in the right direction?

My thoughts about how the computers work and please correct me if I'm wrong. Maybe it will help some people that are having a problem and can't find a solution.

The engine computer and the body computer talk back and forth. When you try to start your engine, the ECM checks the BCM to compare the VIN number. If it doesn't see it or its different, the ECM will not let the starter engage. Seat and Door modules can also cause a problem on the data line so that the ECM and BCM can't commuicate causing a no start. If you unplug a module and it will start, the problem could be in the module. Do not unplug the ECM and BCM as they have to be able to communicate in order for the starter to work. Of course the fuses and relays have to be good. My point is that a bad door module or seat module can give you a problem on the data line that can effect a lot of things on the vehicle that could be over looked. Radio, instruments, locks, windows, etc. Again, this is my thought, not a fact. Correct me if I'm wrong.

Now back to my DIC problem. My thought on it is that the data line must be OK if the trouble lights and gauges in the instrument panel are working so that the problem with the DIC being dead has to be on the board itself. Any help or thoughts would be appreciated.

Sorry for the length but I hope that this helps someone else.;
 
Great diagnosis work on your seat module :thumbsup: :thumbsup: :thumbsup: You're absolutely right on that bad modules can screw up a whole host of seemingly unrelated functions by corrupting the data bus communications.

Is your DIC display out completely or just not responding to the switches? The display portions of the cluster do fail but there are also times when the DIC is off when scrolling through the menus. I was under the impression that they always come on when the vehicle is started though. Try pulling and replacing Fuse 24 (IPC/DIC) in the underhood fuse block. Even with the ignition off this circuit still supplies power to the cluster so you never really get a "hard" reboot unless you pull this fuse or disconnect the battery.
 
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AtlWrk said:
Great diagnosis work on your seat module :thumbsup: :thumbsup: :thumbsup: You're absolutely right on that bad modules can screw up a whole host of seemingly unrelated functions by corrupting the data bus communications.

Is your DIC display out completely or just not responding to the switches? The display portions of the cluster do fail but there are also times when the DIC is off when scrolling through the menus. I was under the impression that they always come on when the vehicle is started though. Try pulling and replacing Fuse 24 (IPC/DIC) in the underhood fuse block. Even with the ignition off this circuit still supplies power to the cluster so you never really get a "hard" reboot unless you pull this fuse or disconnect the battery.
Totally dark or off. I can't remember if I have tried pulling that fuse but I will try tomorrow. Its real disappointing after all the time I put in researching and tracing and then loose the display. I'll let you know what happens. Thanks
 
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linneje said:
Agreed. It happened to me. But I don't think the OP is living in a cold climate.....
It does get cold sometimes. 19 degrees last night but I had this problem in the upper 40's. I tried the fuse reset with no luck. So I pulled the instrument panel and checked all diodes, resisters and transisters. All were OK. I can't check the IC's. Put everything back together and now I have lost power to the radio. I also noticed that the horn honks when I lock the doors with the remote and it hasn't been working. I think that I still got a problem on the data line. Would the instrument warning lights and gauges be working and not get the data for the DIC. Is that possible?
 
AtlWrk said:
There are reports of the DIC display going out in very cold temps and coming back to life when things have warmed up a bit. Other times they're just toast and you're SOL. :frown:

This thread on the old site has a good discussion:
http://forums.trailvoy.com/showthread.php?t=70015
Doesn't look like they found a solution yet. I think it could be a loose connection somewhere. When it gets warm, you get expanison and it makes. That means it could be ANYWHERE. I do know that from my earlier problem that the BCM was turning the radio off and if I have a data line problem somewhere else, I guess it could be turning the radio and DIC off,
 
Radio fixed. Cleaned and tightened grounds on right side of console. Wish I had a good instrument panel to switch with to verify DIC. I think that is the only problem.
 
Midnyteryder196 said:
I might have an 03 cluster coming available this next weekend.. Your choice of leds in it.. It also has New stepper motors as of a year ago
Great if it has the display (DIC) Message a price and maybe a picture when you get it. Thanks
 
I have the same problem as you describe in #3. I also have an open circuit somewhere as the battery will discharge completely with the truck parked for about 3 days. I've installed a new battery and replaced the ignition switch. Tomorrow I'll start looking for the open circuit in hopes that I can isolate the battery and instrument cluster issues.
 
I think I just got a break with my instrument cluster issues (your #3). I started the truck and all the warning lights came on; abs, pkg brake, check gauges with only working gauges being speedo and tach. Also battery charging light on, radio off, etc. I opened the drivers door and slammed it back shut and all the warning lights went off, gauges began workin and radio came on.

I think the issue may be a faulty ground.
 
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FONZ1025 said:
I think I just got a break with my instrument cluster issues (your #3). I started the truck and all the warning lights came on; abs, pkg brake, check gauges with only working gauges being speedo and tach. Also battery charging light on, radio off, etc. I opened the drivers door and slammed it back shut and all the warning lights went off, gauges began workin and radio came on.

I think the issue may be a faulty ground.
There is a ground point on the pillar between the two doors. The plastic covers just snap on. Pull the ones off the carpet first. If the ground is OK, try unpluging the seat module and see if that clears the lights.
 

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