Big problems...

[pajombre03]

So, I have been putting this off for quite some time, because well, it's embarrassing. So I have a 2003 XLS, which is pretty solid. But the speedometer is out. And the traction control and stability control lights are both always on, well they turn on after about 30 seconds of driving. Any way, coincidentally, cruise control does not work, due to the speedo. A weird thing happens. If I turn off the radio before I turn the car off, then when I turn the car on, the traction/stability control lights stay OFF, and I CAN use cruise control, BUT the speedometer stays at zero. Literally, the only time the speedo moves is when the radio is turned way up on a bass-intense song. So, all that weirdness aside, every now and then, around 1-2 times a month, the car will die. At a stop light, the idles will drop, then simply the engine shuts off. Also, it chooses some random curves in the road to die, and the steering wheel tightens up mid turn, which is a major problem. Even though it dies, no matter what, it has not failed to turn back on a single time, and then it'll run good again, until the next death. We have taken it to the dealership, and literally the answer we were given was none. They said to find out more of what it was or could be, we would have to pay, and I mean PAY, just to find out what it COULD be. I'm just wondering if anyone has any suggestions as to what could've happened, what maybe is the best idea to do, maybe some certain things to check on, or whatever else. This is a pretty bad problem, and I guess soon enough I'll have to bite the bullet and drop it off at the dealership for a complete redo. I just wish I could drop the thousands on OME and ARB upgrades instead.
Thanks.

 

[Sabre]

Jeez, it isn't even Halloween yet and your Montero is haunted!

Is your ABS functioning? Speedo and cruise control receive signals (I believe) from the transmission, while traction control/ABS are getting information from wheel speed sensors. If we assume that the SOURCES of your data are OK, then we wonder where the signals are being corrupted. Have your tried reading error codes? Most dealers make you pay for this service, but some don't and the readers are affordable nowadays. Do you have a friend or neighbor that might have an OBD-II reader?

If it's the ECM, you could always buy a used one and swap it out. Of course, this is pretty much the only way of diagnosing the ECM, too! Has the instrument cluster ever been out of the dashboard? The speedo won't work correctly (or at all) if one of the removable circuit boards on the instrument cluster is tightened just a bit too much (DAMHIK). An invisible crack in one of your soldered circuits could easily do this. Replacing the instrument cluster might be worth trying, too.

Both the ECM and instrument cluster swap are literally the work of mere minutes (once you figure out how to get at the screws), and not at all complicated. The cost of these used parts might be a good investment compared with the potential cost of the dealership's experimentation.

Of course, I am not a trained mechanic but merely a cheapskate vehicle owner. Good luck!

 

[off-roader]

I'm suspecting a wire harness issue myself. Installed or repaired anything recently?

 

[pajombre03]

ABS works and functions as it should. No, nothing has been installed or replaced, other than radio, which was a routine radio swap. (As far as I know). The error read thing you were mentioning, sounds like the best path it looks like. I don't understand these problems, they don't make any sense.
Like I mentioned about the cruise control, if i turned off the radio prior to turning the car on, cruise works, but literally as soon as i press radio power button, cruise shuts off, and the two stability/traction control lights come on.

It baffles my mind, but the service shop should be able to fix it. Hopefully.

 

[Monterorider]

Did it behave like that before swapping radio. If not as I suspect whoever installed that radio seriously messed something up.

 

[kuroi]

Two words, CAN BUS.
I'm not 100% but I believe the 03's are Controller Area Network enabled or for sure run a partial CAN. You can't just swap out the radio or install components that interface with the vehicles controller modules like it's 1996 anymore. if you remove a networked component you will cause communication problems in the network which will in turn cause other problems.

From the WIKI
A modern automobile may have as many as 70 electronic control units (ECU) for various subsystems. Typically the biggest processor is the engine control unit (also engine control module/ECM or Powertrain Control Module/PCM in automobiles); others are used for transmission, airbags, antilock braking/ABS, cruise control, electric power steering/EPS, audio systems, windows, doors, mirror adjustment, battery and recharging systems for hybrid/electric cars, etc. Some of these form independent subsystems, but communications among others are essential. A subsystem may need to control actuators or receive feedback from sensors. The CAN standard was devised to fill this need.
The CAN bus may be used in vehicles to connect the engine control unit and transmission, or (on a different bus) to connect the door locks, climate control, seat control, etc.

 

[NH Moto Expo]

Yep...Thats what I was going to guess. Try working with a VW or Audi...the radio is central to the network. You can replace the radio, but you can't just hardwire an old radio in. Call Crutchfield and they can get you the proper wiring module that will make it a plug and play and won't throw codes.

 

[off-roader]

Yep...Thats what I was going to guess. Try working with a VW or Audi...the radio is central to the network. You can replace the radio, but you can't just hardwire an old radio in. Call Crutchfield and they can get you the proper wiring module that will make it a plug and play and won't throw codes.

That's interesting. I wonder if my 01 S4 also requires this extra module for an aftermarket stereo? And how can one tell if it's gone bad? Don't ever recall reading about this on the VWVortex, AudiWorld, or AudiForum forums.

 

[kuroi]

I belive it does, at least i know vagcom can network with the stereo.

 

[off-roader]

I assume this black box is installed between the aftermarket stereo and the oe wiring harness(s)?

 

[NH Moto Expo]

For mine it was built into the wiring harness from Crutchfield. It's not really a black box or module...just making sure that the radio communicates its location with the ECM. And yes when I hook up my VAG COM to my OBD port one of the modules that it looks for is the radio. I believe it's to keep the radio theft resistant.

 

[kuroi]

Its for diagnostic purposes

 

[cnutco]

Has anything been fixed? Have you solved your issue?

I am having the somewhat of the same issue. The same two lights are coming on, but only when my engine starts to misfired bad after it warms up. Only code is B2S1 O2 sensor, nothing about misfire. I have replaced two O2 sensors but I have to look to see which ones.

History:
New instrument panel due to the heat gauge not working
Two new O2 sensors
New NGK plugs
New spark plug wires
New valve cover gasket with grommets
New fuel pump
Injector cleaner in gas

Further plans that I would like opinions on:
Replace coils (wish I did this two days ago with plugs. Palm to face)
Replace other two O2 sensors
Replace catalytic converters
Physically clean injectors
Talk to dealer about the instrument panel they installed

Other ideas are welcomed.