Here's the scenario. 2005 Limited Roadster. 7,500 miles.
The car has been performing flawlessly. Until Saturday.
Backed the car out of the garage and put the top down. I always move the top with the car running.
Drove about 10 miles then the engine stopped while waiting at a traffic light. The engine temp was full normal and car was in drive. RPMs about 500 when it shut down. Put it in park
and it started immediately.
I drove another 10 miles to my destination, pulled into the parking lot and since I intended to stay for a while I put the top up (engine running) raised both windows, shut the car off
and opened the driver's door. I had something in the trunk to take inside so I closed the driver door, walked around back to open the trunk and IT'S LOCKED. I looked at the passenger
door and IT IS ALSO LOCKED. The driver door is UNLOCKED. I tried the unlock button on the fob. NOTHING. Several tries both lock and unlock. NOTHING.
I got in the car and immediately noticed that the odometer, outside temp and trip odo were all blank. Put the key in the ignition (everything still blank)
turned it to ON (everything still blank) turned it to start. NOTHING HAPPENED. Several tries to start and absolute silence. Pulled the key out of the ignition and opened the hood for about 10 minutes.
After 10-15 minutes of wondering what-the-hell-am I-going-to-do-next, I got back in the car and immediately saw that the odometer, temp, etc now displayed as usual. I inserted the key and the car started.
I shut it off (but left it unlocked) and went inside for about 2 hours.
When it came time to leave, the car behaved normally. It started, I put the top down, drove 20 miles home, put the top up and drove into the garage.
Absolutely nothing abnormal.
I've tried both fobs in the garage and they lock and unlock everything normally. I locked it with the fob and unlocked it with the key in the driver's door handle.
UPDATE: Wife and I drove the car to church Sunday evening. All OK except on the way home I noticed at a traffic light that the headlights and
instrument panel lights flickered a little when the car was at idle. Not so when under power. When we pulled into the garage I also noticed
that the overhead light on the windshield header flickered at idle with driver door open. I turned the car off and removed the key. Immediately put it back in
and switched to run, everything lit up as expected but the radio came on. The radio was not on when I shut it off a few seconds ago. (?)
UPDATE #2: The episode where the car ignored everything - no start, blank odometer and temp, no response to remote unlock - lasted about 10
minutes. Apparently the car was in a dead state as the clock is now 10 minutes slow.
Perhaps the fobs need new batteries? Never been replaced I don't think.
There is zero possibility of water in the trunk. The car has never been rained on.
RCM need re-solder?
CPS? I have a new Bosch in the trunk but that wouldn't make the car suddenly ignore my fob (and me) would it?
Maybe the engine shutdown had nothing to do with the car going brain dead for 15 minutes?
Any ideas?

 

CPS / RCM will not cause the displays to be blank.
I suspect one of two things, an intermittent open cell in the battery, or a battery ground cable connection problem.
The fob batteries would also have no relation to the blank displays.

 

Plus 1 on what ala_xfire suggests. Check for loose grounds/cables OR is it possible a rodent got in and is devouring insulation? Slight vibrations could explain some if a rodent has been active. Good luck!


.

 

Thanks, ala. Even though the battery was replaced in March 2014 it is probably not driven enough to
maintain it. The previous owner used a battery tender and the wires are still present, but I have not used one. Should have I suppose. I'll replace the battery this coming weekend.

 

Thanks, Graphite. I have no traces of rodents residing in the garage. No droppings or sightings. Wife would let me know in very short order if she sees one. I'm going to try ala_xfire's battery suggestion. I'll keep your rodent alert in mind in case I still have electrical weirdness after replacing the battery and checking the ground cable.

 

Check the ground cable first, it's much less expensive.

If you have an ohm meter, connect it from the positive (+) battery terminal to the engine.
It should read 12.1-12.4 volts or so.
( you can also use a 12v test light for this )
Wiggle the ground cable and see if the reading/light fluctuates.

 

Thanks. Engine running for the reading?

 

No. 12.1-12.4 with the engine off.
13.8-14.5 if it's running.

 

Thank you, George.

 

Hi Guy's.....
Beeing the Newbie on the site......Could some one explain the SKREEM fix, I have done the batt off, key to on, 15 minutes, key off and Batt on bas erp light now appears, but starts no problem.
The diagnostices show no error codes as everything goes back to normal....I thought error codes were held.....nothing showing....It seems to go back to normal................still not sure about driving it.


Help Please... Ring 175

 

Try turning the steering wheel, completely to the left ,then the right. This works to reset the light ,if nothing else is wrong.
I believe you did clear all codes.

 

delete post

 

I see no foul here Mackel all threads are open for discussion and additional inquiries. This person used the possible cure for the SKREEM problems in his post that has been the subject of some debate and which I added in the thread about Crossfire Problems and Repairs. In your case I would try the reset that he did, you never know and it costs nothing. Remove your RCM from the car, open it up and plug it back into the car and see if the relays are working properly.
After that I would try another RCM, the problem may lay in it.

Ring175, welcome to the forum, I see you are from France.
Presumably this resets everything back to zero in the cars memory, like rebooting your computer after a glitch has occurred.
What were your symptoms before the reset?
I am glad the reset worked.

 

I mean no ill will toward ring175. In fact I welcome him/her to the forum.
I have deleted my post.
No harm intended.

Thank you, onehundred80, for replying about his SKREEM problem.
Ring175...onehundred80 is a wealth of knowledge on this forum.
Welcome!

 

Just an update to this.
A new battery (old one was 31 months old) seems to have cured all symptoms.
Duracell AGM from Sam's at $159.
The battery terminals were in excellent condition as was the ground cable at the body connection.
The ohm meter showed 11.99 to 12.0 volts from the battery at rest and 14.5 with engine running.
Also replaced batteries in both fobs while I was at it.

 

SO, I surmise from your response that an at rest reading of 12.0 volts is NO indication of a good battery !
I guess the only test of a battery is to replace it, and if the problems go with it, then it was bad.
( A cheaper way would be to swap with a buddy, if he inherits your sins, then buy HIM/HER a battery )

Or, if you are mrmiata or reddog, just swap batteries among the dozen or so Crossfires you have all parked in a row.

 

Not at all. I'm certainly not an electrical expert. That's why I sought advice here.
You're the one who suggested that I check the battery and that I should get 12.1-12.4 volts.
Since the terminals were in good shape as was the ground lug, then the battery became the prime suspect.
Given it's age and the fact that I have only 1 toy - go get another one and see if that does it.
It must have been the right medicine. The radio doesn't come on by itself, the lights don't flicker and the car doesn't go totally brain dead on me for 11 minutes.
Thanks for the advice, George.

 

Lights ,brighting and dimming at idle, not much but just enough to notice. Battery, tested good, alternator, tested good, I also had all these symptoms. I replaced the voltage regulator in the alternator and all is fine.

 

Thanks, Steve. If the bug returns I'll know where to look next.

 

Hi George, I try the rule of 2.25v per cell (added up means 13.5v (nominal) but hooked up and under a load it could drop some, it seems? I should go out and V test mine at rest (hooked up). I cannot understand the VERY small load applied (hooked up at rest) would bring it down to 12.1 to 12.4v? Got a little testing to do!


As you are finding out (many have been told for ages, it seems), these cars do not like low voltage/current reserves. When my spoiler popped up I bought a new battery. I still got the old one and it seems to be OK, but no more problems with the XF!


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