Engine Failsafe Mode??? - MustangForums.com


Go Back   MustangForums.com > Ford Mustang Tech > 2005 - 2014 Mustangs > GT S197 General Discussion
Sign in using an external account
Register Forgot Password?
Search


GT S197 General Discussion This section is for technical discussions pertaining specifically to the V8 variation of the 2005 and newer Ford Mustang.

Engine Failsafe Mode???

Reply
 
 
 
 
Thread Tools Search this Thread
Old 05-25-2015, 05:57 PM   #1
Paratrooper34
 
Paratrooper34's Avatar
 
Join Date: Dec 2014
Vehicle: 2005 Mustang GT
Location: Massachusetts
Posts: 31
Default Engine Failsafe Mode???

Ok, got a problem that has me stumped.

I have a 2005 GT automatic with 35,000 miles. I put an Airraid CAI and a tune with a Bama S4 tuner (93r) back in January. About 2 months ago I started the car up to warm it and when I came back out to it, it was showing "Engine Failsafe Mode" (EFM) on the display. Never saw that before, had no idea what it was. So I turned the car off and back on and it was gone.

Since that time, I have been seeing it more often (occasionally). If I turn the car off and back on, it goes away. In addition to that, the car has died on me a couple of times (it lost power, displayed EFM, and then died). I asked a friend and he said maybe the crank or cam sensor needed to be replaced. I decided to try out the code reader on the Bama S4 and it said no codes. So I switched the tune over to the 93s. I haven't run the car on it yet other than to idle in the garage.

So I am at a loss over this. Something must be wrong for the car to display the EFM warning and cutoff on me, right? But no codes on the Bama. Anybody have any insight into this?

Thanks in advance!
Paratrooper34 is offline   Reply With Quote
Old 05-25-2015, 11:52 PM   #2
jwog666
4th Gear Member
 
jwog666's Avatar
 
Join Date: Mar 2008
Vehicle: 03 mustang gt
Location: wisconsin
Posts: 1,314
Default

typically the failsafe mode(sometimes combined with a wrench light) is an indicator of a throttle by wire system concern, these will not always set a code. the fault is usually intermittent and that is why after a key cycle you can start it and drive normally again. with no codes and it being intermittent, this concern will be very hard to diagnose. if after the fault and messege occurs does the vehicle loose throttle response? if so you are probably looking at a throttle body or accelerator pedal assembly issue. good luck
__________________

Kenne Bell 2.1 Twin Screw (9 PSI), Kenne Bell Big tube kit, Pypes catted x pipe, Pypes violator catback, Steeda tri-ax, 3.73's, Spec stage 1 clutch, tail light sequencers, Mach 1 grill delete & chin spoiler 405HP 427TQ at the rear wheels
jwog666 is online now   Reply With Quote
Old 05-26-2015, 04:48 AM   #3
Paratrooper34
 
Paratrooper34's Avatar
 
Join Date: Dec 2014
Vehicle: 2005 Mustang GT
Location: Massachusetts
Posts: 31
Default

[QUOTE=jwog666;8487543]typically the failsafe mode(sometimes combined with a wrench light) is an indicator of a throttle by wire system concern, these will not always set a code. the fault is usually intermittent and that is why after a key cycle you can start it and drive normally again. with no codes and it being intermittent, this concern will be very hard to diagnose. if after the fault and messege occurs does the vehicle loose throttle response? if so you are probably looking at a throttle body or accelerator pedal assembly issue. good luck[/QUOTE

Thanks for the quick reply, jwog, looks like you are on to it. Here is some new info:
Drove it to work this morning. FEM light came on after a couple miles or so. Turned it off and on, it went away. A minute or two later, it came back on again only this time it was accompanied by the check engine light. Would not go away by turning it off/on.
Brought my scanner to work and came up with these two codes: P2106 and P2135.
P2106 is "Throttle actuator control system - forced limited power"
P2135 is "Throttle/pedal position sensor/switch "A"/"B" voltage correlation.
Would throttle position sensor be the right choice?
Paratrooper34 is offline   Reply With Quote
Old 05-26-2015, 06:08 AM   #4
jwog666
4th Gear Member
 
jwog666's Avatar
 
Join Date: Mar 2008
Vehicle: 03 mustang gt
Location: wisconsin
Posts: 1,314
Default

yes, the entire throttle pedal assembly should be replaced, assuming that there is not a concern with the wiring(its more common that the pedal be faulty, but there always is a chance of bad wiring), i have changed many pedals that have failed just like yours
__________________

Kenne Bell 2.1 Twin Screw (9 PSI), Kenne Bell Big tube kit, Pypes catted x pipe, Pypes violator catback, Steeda tri-ax, 3.73's, Spec stage 1 clutch, tail light sequencers, Mach 1 grill delete & chin spoiler 405HP 427TQ at the rear wheels
jwog666 is online now   Reply With Quote
Old 05-26-2015, 07:06 AM   #5
Paratrooper34
 
Paratrooper34's Avatar
 
Join Date: Dec 2014
Vehicle: 2005 Mustang GT
Location: Massachusetts
Posts: 31
Default

[QUOTE=jwog666;8487554]yes, the entire throttle pedal assembly should be replaced, assuming that there is not a concern with the wiring(its more common that the pedal be faulty, but there always is a chance of bad wiring), i have changed many pedals that have failed just like yours[/QUOTE

I checked rockauto.com for the part and I see two that are related to what you said. There is a Accelerator Pedal Position Sensor (attaches to the accelerator pedal?) and a Throttle Position Sensor (not sure where that goes). In your reply, are you referring to the Accelerator Pedal Position Sensor?
Paratrooper34 is offline   Reply With Quote
Old 05-26-2015, 07:37 AM   #6
jwog666
4th Gear Member
 
jwog666's Avatar
 
Join Date: Mar 2008
Vehicle: 03 mustang gt
Location: wisconsin
Posts: 1,314
Default

the accelerator pedal position sensor is the one you need, the p2106 is to tell you that there is a throttle system problem and that idle is forced, the p2135 is to tell you that the throttle pedal sensor (there are actually 2 in the pedal a and b they have inverse voltages and need to indicate the same % of throttle as each other) is faulty.
__________________

Kenne Bell 2.1 Twin Screw (9 PSI), Kenne Bell Big tube kit, Pypes catted x pipe, Pypes violator catback, Steeda tri-ax, 3.73's, Spec stage 1 clutch, tail light sequencers, Mach 1 grill delete & chin spoiler 405HP 427TQ at the rear wheels
jwog666 is online now   Reply With Quote
Old 05-26-2015, 08:27 AM   #7
Paratrooper34
 
Paratrooper34's Avatar
 
Join Date: Dec 2014
Vehicle: 2005 Mustang GT
Location: Massachusetts
Posts: 31
Default

Quote:
Originally Posted by jwog666 View Post
the accelerator pedal position sensor is the one you need, the p2106 is to tell you that there is a throttle system problem and that idle is forced, the p2135 is to tell you that the throttle pedal sensor (there are actually 2 in the pedal a and b they have inverse voltages and need to indicate the same % of throttle as each other) is faulty.
Ok, got it! Thanks so much for your help! I will let you know how it turns out. I see you are far away from me, but if you are ever in New England, beers on me.
Paratrooper34 is offline   Reply With Quote
Old 05-26-2015, 08:37 AM   #8
jwog666
4th Gear Member
 
jwog666's Avatar
 
Join Date: Mar 2008
Vehicle: 03 mustang gt
Location: wisconsin
Posts: 1,314
Default

lol no problem. i like getting to the bottom of problems
__________________

Kenne Bell 2.1 Twin Screw (9 PSI), Kenne Bell Big tube kit, Pypes catted x pipe, Pypes violator catback, Steeda tri-ax, 3.73's, Spec stage 1 clutch, tail light sequencers, Mach 1 grill delete & chin spoiler 405HP 427TQ at the rear wheels
jwog666 is online now   Reply With Quote
Old 05-30-2015, 02:27 PM   #9
Paratrooper34
 
Paratrooper34's Avatar
 
Join Date: Dec 2014
Vehicle: 2005 Mustang GT
Location: Massachusetts
Posts: 31
Default

UPDATE....

Ok, got the part swapped out today. Cleared the codes out and the check engine light is gone. Took it out for a ride and damn it, the car died on the road while driving. Lost power and shut off. This is what it was doing before. Turned it back on, it was fine until it happened a little while later as I was pulling into my driveway. No check engine light, nothing. Now I am really stumped.
Paratrooper34 is offline   Reply With Quote
Old 05-30-2015, 03:18 PM   #10
jwog666
4th Gear Member
 
jwog666's Avatar
 
Join Date: Mar 2008
Vehicle: 03 mustang gt
Location: wisconsin
Posts: 1,314
Default

it could be a wiring issue from the pcm to the sensor
__________________

Kenne Bell 2.1 Twin Screw (9 PSI), Kenne Bell Big tube kit, Pypes catted x pipe, Pypes violator catback, Steeda tri-ax, 3.73's, Spec stage 1 clutch, tail light sequencers, Mach 1 grill delete & chin spoiler 405HP 427TQ at the rear wheels
jwog666 is online now   Reply With Quote
Old 05-30-2015, 03:18 PM
MustangForums
Ford Mustang




Paid Advertisement

 
 
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

 
Advertising
Featured Sponsors
Vendor Directory
New Sponsors
All times are GMT -5. The time now is 12:55 PM.>

© Internet Brands, Inc.


This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company
Emails Backup