2008 Mercury Mariner HELP!

January 21, 2010 1:01 PM

I have a 2008 Mercury Mariner. Recently, all of the dashboard lights light up like a christmas tree (and stay lit) and the gauges all sweep to the end and then stop back at zero while I am driving. Once I shut the engine off, the car will not start. This does not happen all the time but enough that it left me stranded twice in the past week. I have replaced the battery. This did not help. Through trial and error, I learned if I hit the alarm button, then attempt to start the car, it will start and I will be able to drive until the entire process repeats itself. I have it at the dealer now and after 72 hours, they still have no idea what's wrong with it. The dealer has said that their diagnostic equipment is identifying "communication codes to cluster" but I have no idea what that means. Any ideas on what could be causing my mysterious Mariner problem? I am in the Northern NJ/Rockland County area (if you have any suggestions for shops to try).
posted by starsixnine00 to Travel & Transportation (9 answers total)

"Cluster" in this usage most likely refers to the gauge cluster in the dash. It sounds like there's a glitch in the wiring, or with an input/output circuit board, or with the dash circuitry itself, or with the way the alarm interfaces with some of the above. This might be very hard to pinpoint, but the shotgun approach of simply replacing all of the involved components isn't very practical. A really good auto electronics technician can typically pinpoint this sort of issue within a few hours, but the average dealership mechanic may not have the right tools and/or experience to do this -- not knocking them at all, but rather acknowledging that this sort of troubleshooting is very specialized, and it is time consuming to do correctly.

You may want to propose taking it to a specialist and having the dealership pick up the bill -- this may be a better use of their time and money. Or, if things are slow, they may be just as happy to let their techs chew on this for a while before conceding defeat.

Good luck!
posted by mosk at 1:17 PM on January 21, 2010

My guess is that there's an error with the alarm system that causes it to go into an "I'm stolen" mode while being driven. It won't kill the car immediately (holy traffic pileup, Batman!) but it probably kills all inter-module communications (including the speedo, which is driven by the ECU). Once you hit the alarm button, it "disarms" the system and resets the start disable.

You need to stay on the dealership about this. This is surely a warranty-covered issue, and lemon laws might come into play at some point.
posted by TheNewWazoo at 1:21 PM on January 21, 2010

Whenever I've had problems with cars starting, gauges acting funny and alarms behaving weirdly, it tended to be a problem with fuses. Has that problem been ruled out?
posted by abdulf at 1:22 PM on January 21, 2010

Don't know if it helps, but does that happen when you start the car? Could be something in the car's brain telling it that it's starting.
posted by InsanePenguin at 1:28 PM on January 21, 2010

What I meant was that, when I start my car all the dash lights go on for a minute and the gauges zoom all the way up and then back down to where they should be. Like a little start-up animation but for a car.
posted by InsanePenguin at 1:29 PM on January 21, 2010

Response by poster: I'd also like to add that the car is about 12k miles out of warranty and the dealer has no loaners and is charging me $30/day for a rental. Keep the suggestions coming as these are all things I intend to bring to the dealer. Thanks for the brilliant suggestions.
posted by starsixnine00 at 1:33 PM on January 21, 2010

My own car started showing similar symptoms when the alarm system developed...issues. The mechanic determined that the car was no longer recognizing the key's chip, and ultimately fixed the problem by replacing the electronic elements in the ignition that link to the security system.
posted by thomas j wise at 1:38 PM on January 21, 2010

If the vehicle will operate without the remote security system, remove that fuse and see if the fail condition still occurs. There could be a fault condition in the Smart Junction Box (passenger side of the center console) which is causing the gauge cluster to freak out. Another thing to check would be a fault condition within the Passive Anti-Theft system. On one of my old vehicles with a Passive Anti-Theft system the ignition cylinder wore out to the point where every once in a while it wouldn't recgonize the equally worn out key and the car would go into "anti-theft" mode and would have to sit for 20+ minutes to start. Eventually this ended up leaving me stranded when the key would not be recgonized at all. So, I had to have a new ignition cylinder keyed and installed. However, IANA mechanic and without being intimately familiar with the undoubtedly complex electronics of this vehicle it's hard to pinpoint an exact cause.
posted by ganzhimself at 2:00 PM on January 21, 2010

Best answer: Ok, so most newer cars have an integrated network called CAN bus. CAN is short for Controller Area Network. This is a high-speed network in your car that allows important data to pass quickly from one control module to another. This ultimately reduces the number of redundant wires and sensors and allows control modules to share information with each other. For instance, the transmission computer, engine computer, ABS computer, instrument cluster (dashboard/gauges), and airbag computer all want to know how fast the car is going, if you're pressing the brakes, etc. So instead of running half a dozen wires and redundant sensors, they just share that data on a high speed network, which your "cluster" is a part of. If they're getting codes for "no communication with cluster" those errors are being stored in other control modules that are looking to receive some information from the cluster.
Either there's an intermittent physical break in the network wiring to the Instrument cluster or the power supply to the cluster is cutting out while the vehicle is operating.
I don't know all of the details of the Mercury network, but some control modules have multiple responsibilities. Just a guess, but the anti-theft/remote locking control could be part of the instrument cluster control modules function. Or, the immobilizer could be on a sub-network and the instrument cluster puts that sub-network's data onto the CAN bus.
Depending on how the network is physically laid out in the vehicle wiring, and how the physical wiring "nodes" (junctions) are assembled, this could take quite a bit of time. Some manufacturers, like Audi for instance, engineer service points for this network where a bridge connector can be removed and a pin-out box can be installed for diagnosis. This, however, is expensive and not every auto maker goes to that expense or trouble.
posted by Jon-o at 6:30 PM on January 21, 2010 [1 favorite]