Had been having weird issues with my dash. Service light coming on and off, had it scanned,no faults. Drove a long trip over the weekend and the service light was going on and off, service engine soon light going on and off simultaneously either the speedometer, tach or gas gauge would drop to 0 until both service lights went out. After arriving home there was a hot electrical smell from under the hood. Checked the fuse box and the window control relay was a bit warm, but not hot. After doing some research I sent my BCM to a company that diagnosis and repairs them. They just called this morning to say there is no problem with it. So, any idea where I go from here?
Thanks

 

I'd check all of my ground wires. But I'm not a mechanic.

 

loose connector on cluster? Loose ground on cluster?

Sure sounds like BCM acting up. I believe it controls all of the items you described.
Maybe there is a bad ground AT the BCM. What I mean is that most of the circuits internal to the BCM already have 12V or 5V or what ever being supplied to them, Instructions from wherever come along to the BCM as a "REQUEST" to do something. For example, if the ECTS detects the coolant getting too hot, the circuit that infers the coolant temp sends a request to the BCM to enable the cooling fan under the hood to keep the engine from overheating.

In my example, a BCM pin is taken to ground internally. The wire attached to the pin outside goes to ground, the fan relay, closes, the circuit is completed, and the fan turns on.

If you have multiple stuff popping on and off like the service and SES lights, and other things disappearing like the fuel gauge reading, it sounds like some circuits are improperly being grounded (the idiot lights, but others str going open circuit.

I would start at the BCM and check all connectors for dirt and corrosion. Did this start immediately after a rain or snowstorm?. It is a very odd combination of symptoms that usually indicates a failing BCM. Having things pulled to ground and pulled away from ground sound like two separate issues to me, electrically speaking.

Did 100% of the things that are acting up begin to do so at the exact same time? This is critical.
Please answer this question before going on a wild wiring goose chase

 

The service light started coming on and off a couple weeks before only after the car got warmed up and the heater was on for awhile. Then on a long trip the SES light also started coming on and the gauges stated going off and on. I used to work on main frame computers and would have to reseat and or clean contacts and reseat circuit boards all the time. Was going to do that on the BCM but everything I read pointed to it being bad. They said 2003 was the worst year for them, so I just sent it in.
Thanks for the help. Anything else you could add may be helpful.

 

If it is coming and going like that, it REALLY sounds like BCM going bad. I don't really know how they would test one unless they have a rig with 99 million BCM internal schematics and are exercising every single function the thing can perform

Can't hurt to clean the contacts on the bcm and at the cluster.

Could try getting it reflashed or going to a yard and getting the same part number from a car with similar options and getting that refleashed

Please let us know

 

I've had this happen as well. Found the battery pretty well fried. No issues since I replaced it.

 

Indeed, any electronic system not fed enough current at the right voltage will perform erratically.

But OP needs to tell us if they have other symptoms that would indicate a bad battery -- like vehicle difficult to start, can't hold a charge overnight.
Without said information, I can only go on the info I am given.

Thanks for your input Tshardin, (sincere, not sarcastic).

 

As for BCM's from junk yards. Remember one thing. Whatever mileage is on the vehicle in the yard is what will be on your cluster when you install it because that is where a Vue stores it's odometer reading. I deal only with 2002 through 2007 Vue's and from my experience I have never had issue swapping BCM's between years as long as the add on equipment such as ABS or traction control are matched. I have like 15+ BCM's on hand and made the mistake not knowing this when I removed them from vehicles in the beginning, only marking them with mileage and not with or without additional options. I can still use them but I have to sometimes program more than one to get the options correct. Don't repeat my mistake when you remove one!

Now, as for part numbers. As long as you ensure that if your vehicle has ABS or traction control or options along those lines get one from a vehicle with those options or you will have a warning light lit in your cluster once the BCM is installed and you won't get it out. As for 4 cylinder / 6 cylinder / CVT / automatic or standard transmissions the BCM's do not see the differences there. I know this from numerous BCM swaps during troubleshooting and repair. I keep numerous BCM's on hand.

Yes, battery voltage / available current and good grounding most definitely effects proper operation of the BCM.

Additional information: ECM's on the other hand are programed and wired internally in accordance to whatever "Type" transmissions they are originally built with. Get the wrong one installed and it probably will run but will more than likely run in reduced power mode. I found this out trying to run a CVT ECM with a 5 speed transmission after converting to a 5 speed.