Tachometer not working properly/lights flickering

[M_viper]

Hi, my 08 tachometer hasn't been the same for a couple of days. The tachometer tends to lag/ stick at some rpms and then just flys so basically I can't tell when to shift and what is my actually rpm. On the other hand everytime I turn the car off the lights on the whole dashboard starts to flicker on and off for a couple of times. Could this be a bad alternator?

the voltage is lower then 14 while the car is on.

I'll post a vid asap so you guys know what I mean


Thanks

 

[Steve-Indy]

Test battery and alternator...I'm guessing battery.

 

[M_viper]

checked on the battery and it's good

also plugged in the obdII and came up wih this code U0140

 

[Detlef]

Not sure what it means but this site says

U0140

Lost Communication With Body Control Module

 

[BlknBlu]

i found this.

You will need to verify good power/ground on body control module...then check data wire between PCM and body control module..If all wiring is good replace body control module. You can disconnect/reconnect the module a few times to see if that helps, sometimes its just a poor connection.

Bruce

 

[M_viper]

In the works , thanks everyone will update as soon as I find out whats going on, but as soon as this happened shifting through gears tended to be much worst.

did a little search and came up with this:

Bulletin Number: SB-08-07-30-021
LOSS OF HIGH SPEED GMLAN COMMUNICATIONS, INTERMITTENT NO CRANK, IPC GAUGE FLUCTUATION, INTERMITTENT DOOR LOCK CYCLING, TRANSMISSION MAY NOT SHIFT, DTCS U0073, U0100, U0101, U0102, U0121, U0140 SET (REPAIR BACKED OUT TERMINAL IN TRANSMISSION


from this site

http://db.theautochannel.com/db/use...8-Cadillac-XLR-Convertible,,&cars=24907,21875

 

[ROCKET62]

First - have you had ANY work done, made ANY changes/mods recently?

Agree with the others - sounds like a loose connection or loose ground. Check the connections to the PCM at the front left of the engine bay.

 

[M_viper]

got balenger - PCM - intake filter..have been on for a year now and no problems

but I did have a recent interior change + installed the new ipod interface and that problem occured right after it.

I'm doubting that any changes in the ipod interface would make that because it's just a plug on.

 

[M_viper]

this is what I mean

http://www.youtube.com/watch?v=8t5rw4n3hJs&feature=youtu.be

 

[M_viper]

update: after changing the body control module the dealer found out that this problem is coming from the OEM stereo/radio system which I reccently connected the ipod interface to it. So something must have triggered something.

could it be from the sirius radio receiver because I do recall that this has something to do with the ipod interface but I'm not sure.


I might aswell just change the whole stereo , any recomendations?

 

[Coloviper]

Nope, it is from the iPOD Adapter interface cable. Mine is an 06' but it did the exact same thing wth gauges and windows acting weird. We pulled it back out and researched it further at the time. I don't know how companies are able to continue selling an iPOD adapter that continues to have these same isues on every install.

However, turns out it is a problem with pin outs and wiring in the iPOD adapter cable (Thank you to the masked man in the VCA who helped me out at the time). Someone on this site helped me out years ago and maybe they will surface to help you out as well. We ended up using the cable from a Jeep SRT iPOD Adapter kit from the Stereo Head unit to the iPOD Adapter module. The one for a Viper from Dodge and a few others does not have enough wires and some of the pin outs are in the wrong spot.

Anyway we fixed that on mine and that fixed it for good. 4 years working great and trouble free. I also have 08' Nav unit stereo in mine now, iPOD Adapter and Sirius SAT radio in addition ot the in my car too. It is not the Sat Radio but the iPOD Adapter cable that is your problem.

 

[M_viper]

Thanks Coloviper for your help.

The car is running smooth now with the stereo disconnected. I agree it is the ipod interface although I did buy it off the viper parts but I have no clue to why it did this.

So I'm going to reconnect the stereo and disconnect the ipod interface and see if that solves the problem. Hopefully the masked man could help me out too

 

[M_viper]

Update:

Fixed the problem, turned out that the whole ipod interface was doing all this. Disconnected the ipod interface and the car went back to normal after a restart.

Thanxs coloviper for your help.

 

[85 of 200]

It's the iPod adaptor, pm me and I can tell you the issue. Your missing a wire. Pm me and I'll give you mY number. The factory harness has a wire that is missing when you connect the sat, iPod and radio. If you only do radio and iPod, or radio and sat, you will be fine.

 

[01sapphirebob]

It's the iPod adaptor, pm me and I can tell you the issue. Your missing a wire. Pm me and I'll give you mY number. The factory harness has a wire that is missing when you connect the sat, iPod and radio. If you only do radio and iPod, or radio and sat, you will be fine.

Good info!! I'm looking to do this kit soon and this is a big help.