Hey everyone,


I swear my 04 C2 Cab is electrically possessed! I've been dealing with it for 2 weeks, but not driving it. Awhile back, it lit up the Brake and ABS lights and the ABS System light flashed up but everything cleared in a few seconds.


The next day, it all happened again, but also flashed up a red light that has a box with an electrical (zigzag shape) inside it. Cleared that with the paddle on the steering column. Then I got an "instrumentation failure" caution, which I cleared. Then a check engine caution that I cleared, plus a check engine light down by the brake/ABS lights. Every once in a while, a temperature failure caution would show up but I could clear it. When the last one showed, I'd get an overtemp idiot light, but the gauge never read over 180.


Here's the kicker. The tach and speedo stop working whenever the check engine caution comes on and the rear spoiler retracts and deploys continuously!


I drove it down to Auto Zone to have codes read, but there were no engine codes to show. I've already replaced the ignition and clutch switches, since everything I've read pointed to them being the most common culprits. I've disconnected the battery and shorted the cables together to clear the computer per my indy's recommendation.


I've read it could be the MAF sensor and am getting ready to disconnect it to see if that's the problem. They thought I had a bad MAF back in February when I had the IMS/flywheel/clutch replaced. Come to find out, it was a bad AOS. Now I'm wondering if oil/junk came from that and contaminated the MAF?


Anyway, it's driving me crazy not being able to drive the car, especially after getting a new top this week! Any suggestions would be MOST appreciated before I throw my checkbook to the indy.


Thanks!


Phil

 

I would put a new battery in, cheap fix if it works, seems an iffy battery can cause a plethora(three amigos-El Guapo) of problems...

 

Rodents chewing cables?
Get your Indy to plug in their diagnostic tool,to see if there are specific codes that a standard OBDII reader can't pull up.

 

Have to second Bal's idea regarding rodents.

Often when little used cars manifest electrical problems out of the blue it is due to rodent damage.

My suggestion is you carefully inspect the car for rodent sign and damage.

While you are at it check for any signs of moisture in the cabin, for damp carpets, damp door bottoms, etc.

Look at the body drains for any signs of blockage.

Also, the top can leak. My Boxster's top has developed a leak that drips water onto the wind blocker that spans the space between the roll bar hoops. But I can also hear water dripping somewhere else but I can't find the leak. Top is due to be replaced next week. In the meantime no more car washing.

A bum battery can result in the car manifesting electrical gremlins. Some systems are more sensitive than others to insufficient electrical power and ABS, PSM are examples.

If not a bum battery then a bum alternator. But I'd look to the battery first. A load test down early in the morning then again at closing time can identify a battery on its way out.

If the battery proves to be ok then a charging system test can be used to determine the alternator is or is not putting out enough electrical power.

 

Guess it's a call to my indy tomorrow. I took the battery in to be tested and it was fine (purchased in March of last year). I'll poke around for rodents, but the car is garaged every night and was my DD until this happened. I don't think it's a moisture problem from the simple fact it rarely sees water except for a bath from a hose and I stayed away from the old top for that reason. It's a weird day when the humidity goes above 50% here in the high desert, too.


Thanks for all the great pointers and I'll continue looking!


Phil

 

We spent many months eradicating rats from our crawl space. They actually chewed through the wall to get into the garage. We keep dry dog food in the garage and they just love that. We ended up renting one of the PODS containers, moved and cleaned what we wanted to keep out of the garage and into the pod, and dropped off about 1000lbs of rat dropping infested stuff at the dump. Yuck.

 

Had a new battery installed in my Turbo and 7 months later the battery as dead. Newness of a battery does not guarantee a good battery. They can fail/go bad at any time.

Doesn't get that humid where I am either but more than a few times a change in the weather, a drop in temperature with a bit more humidity and the Turbo (or the Boxster) will misfire upon cold start. It seems the engines just attract moisture out of the air. Might be the dust on the engine hardware. Both are due -- overdue -- for new coils. Next time I have either car in for service I'll get new coils installed.

Rodents are good at keeping out of sight.

Best advice I can offer -- picked up over the years -- is to be sure where the car is parked the floor is clear of boxes and other items the animals can use to make their way around without being seen. Shelves, cabinets are highly recommended to get things off the floor. The creatures can still move about at night but they like to hug the walls so traps set out along where the floor/wall join will catch them.

I would not rely upon things designed or intended to keep them out of the car. The problem is they have to get in the car to be affected by these, if "these" even work, and I prefer to keep the animals out of the garage and as far away from the car as possible.

Any gaps around pipes or whatever that mice can get though, and they can fit through some pretty small gaps, should be stuff with steel wool. The mice can't chew or pull this stuff out.

Ball brought up a good point and that is put all pet food up and store it in such a way the mice can't get at it.

Mice or rats.

Some years ago when some old houses in the neighborhood were being knocked down to build new houses and the old houses and out buildings and piles of firewood were removed this disturbed a number of rats and afterwards my house and those of my neighbors had rat problems.

In my case the damned things were coming in through the back door of the garage though the doggy door. I put up the pet food but still I had a heck of a time until I was told to put the rat trap on top of the dryer. The slick enamel paint on the clothes dryer did not give the rat sufficient grip to jump back before the trap sprung and I caught one in just a day or two and the second one the next night and that was that.

 

rodents got into my engine ,chewed thru several cables causing o2 sensor to show up on dash, $700 to fix..i put a piece of bait in engine and haven't seen them since...you will know if you have rodents, they leave their little calling cards

 

My indy had the car for several weeks and finally threw in the towel after spending 15 hours on it without billing me for that. Here's a run down of what he tried and observed:


Codes


DME:
P1600 CAN timeout PSM (no signal)
P1601 CAN timeout Instrument Cluster (no signal)


ABS:
-5520 CAN bus data (open circuit)
-5525 faulty data exchange from DME
-5555 CAN message missing instrument cluster (open circuit)


Instrument Cluster:
-9111 PSM/ABS control unit (no signal)
-9110 DME control unit (no signal)
-9101 CAN drive bus (no signal)


Tested with new parts: MAF, alternator, ignition switch
Replaced instrument cluster with used unit that has 17K miles.


It threw messages for the first couple of miles on the way home, but cleared up and I thought I was good to go. The next day, all hell broke loose and I'm back to square one with all the messages again!


The only thing we haven't done is send out my cluster for repair and I guess that's next on the list, along with going over all the grounds again, even though my mechanic said he's looked at just about everything. He didn't get any suggestions from a Porsche tech group he's a member of, so I may be looking at some major problems.


Does anyone have any suggestions?

 

CAN bus is a cable pair running from DME to numerous points.(some have used CAT5 twisted pair for running new lines) Seems you have a break in the cable somewhere. Pull up a wiring diagram and check continuity.