Fail Safe Mode

kerosene hat · 08-10-2006, 07:11 PM

is this something major? i am interested in finding out as much info as i can before the dealer can give me a line of hoooey ..

had the car in 2 weeks ago for a random knocking noise coming from the engine..http://www.ford-forums.com/images/smilies/mad.gif

they say oh we can't find anything wrong with it.. I believe them...

tonight my wife is on her way home and the little orange wrench lights up and across the display it says FAIL SAFE MODE.. she calls i say go to dealer now...
gets to dealer and service manager says oh you were here 2 weeks ago?..http://www.ford-forums.com/images/smilies/mad.gif

http://www.ford-forums.com/images/smilies/eek.gif

http://www.ford-forums.com/images/smilies/confused.gif

the other service manager lady says yes i remember her... she had the knocking noise..
oh he says..

they keep the car and give us a taurus...

more info to come..

if anyone has experienced this please Respond ASAP?
please..

PsyDoc · 08-11-2006, 07:04 PM

There is a technical service bulletin (TSB) out on how to deal with the problem, if it is an issue of the rocker arms. Basically, the TSB says to remove the valve cover, tighten the bolts to the correct torque setting and then reinstall.

PsyDoc · 08-11-2006, 07:14 PM

I did a little checking and the "Fail Safe Mode" allows the vehicle to be driven a short distance without damaging the engine. The knocking could have been the valves and/or rocker arms loosening. Good think the car is still under warranty.

strongoak · 08-21-2008, 09:18 PM

I spoke with the ford repair shop manager and was told that the fail safe mode was to protect the transmission. I really do not think that it is a transmission problem. My best guess is that a wire may be shorting causing the problem. Disconnecting the battery for five minutes didn't solve the problem. The car will reset upon turning off and restarting. It will run about 200 miles and go into fail safe again. I have posted my problem with other information about the problem under failsafe engine mode. The ford manager stated that they charge $94.00 per hour. If you have a code reader you can most likely get a code if you run test before shutting down the engine while it is still in failed mode.

strongoak · 09-11-2008, 06:34 PM

Have you solved your problem with the fail safe mode yet? The problem can also be caused by a blocked air filter or maf sensor.

theoldwizard · 09-11-2008, 06:49 PM

Quote:

Originally Posted by strongoak

Disconnecting the battery for five minutes didn't solve the problem.

It takes an hour or more of a disconnect battery for the PCM to "forget".

BroncoJoe19 · 09-11-2008, 08:15 PM

First of all you guys are respondeing to a two year old post.... AUgust 2006!

Next... why is it that people have a mechanical or electrical problem that they think that by removing the battery cable the problem will go away!?

This may relate to fail safe mode...
Failure Mode Effects Management (FMEM)
FMEM is an alternate system strategy in the PCM designed to maintain vehicle operation should one or more sensor inputs fail.
When a sensor input is perceived to be out-of-limits by the PCM, an alternative strategy will be initiated.
The PCM will substitute a fixed in-limit sensor value and will continue to monitor the faulty sensor input. If the faulty sensor operates within limits, the PCM will return to the normal engine running strategy.
Engine Running DTC 98 or 998 will be displayed when FMEM is in effect.
The Malfunction Indicator Lamp (MIL)/Message will remain on when FMEM is in effect..."

AND Limp Mode may also relate to fail safe mode.
so, E4OD Limp Mode; happens when the vehicle computer recognizes a problem in it's logic. When an expected signal value from a sensor is sent to the computer and is not within the computer's programmed specifications, "secondary" programs are activated by the computer to strive to protect the transmission from damage the improper sensor signal might cause to occur. In other words, the computer is always expecting certain signal values from certain sensors i.e. the temperature sensor, the speed sensor, the throttle position sensor, etc. As long as these signals are what it would normally expect for the conditions and is normal based on all the other signals it is receiving from other sensors, it acts normally and accordingly. read more.... Source: by autotransinc.com - site is gone - via webarchive.org finally via miesk5 at broncozone.com

strongoak · 09-15-2008, 07:14 PM

Code 2135 indicates a throttle pedal position sensor. Replaced, ran about 200 miles and it went into fail safe mode again. Replaced dirty air filter and cleaned maf sensor and so far no problem. Obviously the computer sent the wrong code or another element caused the mismatch in pedal sensor that set the code. I am curious why it would take an hour or more to affect the pcm. Could you explain. Thanks

BroncoJoe19 · 09-15-2008, 08:45 PM

Did you disconnect your battery cable?
Unless OBDII is different from OBDI then disconencting the battery cable to celar codes causeing the EEC to loose the data it had collected for its adaptive strategy.

theoldwizard · 09-16-2008, 04:21 AM

Quote:

Originally Posted by strongoak

I am curious why it would take an hour or more to affect the pcm.

By decree from the EPA, the PCM must remember error codes and other "adaptive information" across a battery disconnect (I don't remember exactly the number of minutes, but it is something like a minimum of 10-15). This is done by charging a small capacitor (an electrical component inside the PCM that is somewhat like a rechargeable battery, but will only last minutes) internal to the PCM that powers the "keep alive" memory.

I have heard that in the not too distant future (2010?) that Diagnostic Trouble Codes will have to be stored in true "nonvolatile RAM". This means that they will be saved even if the PCM is disconnected for months !