Engine safe mode? Limp mode?

When you remove power from the system and then hook it up again it can get mixed up kind of like when you boot a computer sometimes you need to do it more than once to get it to initiate.

You probably need to clean the throttle bore here is a guide to help fix it.

https://www.2carpros.com/articles/throttle-actuator-service

The aftermarket industry has come up with all kinds of "memory saver" devices designed to allow the battery to be replaced without having to go to the dealer. Some just plug into the cigarette lighter, but you have to have a car where the lighter works with the ignition switch turned off.

Well I hope this helps out other people. Thanks for the replies.

I have two vehicles with built-in factory anti-theft systems. Both have less than 5,000 miles, and I rarely drive them. My daily drivers do not have anti-theft systems, and don't need them.

Engine Mechanical problem 6 cyl Four Wheel Drive Automatic 88000 miles

Hello, recently my ford explorer 2005 would not start. I used jump box and vehicle started up. I turned on defroster waited 10 min and went in house. Came back 10 min later vehicle was off. Bought new battery i installed and now have message engine fail safe mode and vehicle wont start. Can anyone help?? My only vehicle.

Hello,

I would check the alternator output first this could be why the first battery lost its charge. Here is a guide to help

https://www.2carpros.com/articles/how-to-check-a-car-alternator

If the alternator is okay let's start by running the codes to see what come up which shoulds tell us why it is in limp mode.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

I have seen where the throttle body receives a voltage surge and goes out. In this case you will need to change it out. Here sia guide to show you what you are in for.

https://www.2carpros.com/articles/how-a-throttle-body-works

Please let us know what happens.

Cheers, Ken

Hello,

I would check the alternator output first this could be why the first battery lost its charge. Here is a guide to help

https://www.2carpros.com/articles/how-to-check-a-car-alternator

If the alternator is okay let's start by running the codes to see what come up which shoulds tell us why it is in limp mode.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

I have seen where the throttle body receives a voltage surge and goes out. In this case you will need to change it out. Here sia guide to show you what you are in for.

https://www.2carpros.com/articles/how-a-throttle-body-works

Please let us know what happens.

Cheers, Ken

Last Thursday I was driving home from work in a 35 mph speed limit zone, and I had to come to a stop because a truck thought he wasn’t going to make it under a railroad bridge. About thirty seconds later, he starts driving and I look down at my dash, and the “Engine Fail safe Mode” message displayed, and the car stalled. I was able to start it up and drive it home without further problems. Took it up the highway later that day, and no issues. Took it to a mechanic over the weekend and they couldn’t figure it out because it didn’t throw any codes. Drove it home from the mechanic with no issues, and to work this morning with no issues. Driving home today, down that same 35 mph speed limit road, “engine Fail safe Mode” displayed again, and the orange wrench light lit up like it did last week, but this time it didn’t stall, not even after coming to a complete stop in my driveway. Left the car running for a couple minutes and it still didn’t stall but the light was still on. I had a similar issue with it about five years ago where the message kept popping up very frequently and the truck would stall while slowing down to take a turn; it turned out to be the throttle sensor was bad, so we replaced it and all was fine until now. The only thing is the “check engine” light, or in my case, the “service engine soon” light didn’t come on, which explains why it didn’t throw a code. I can’t remember if that happened five years ago or not. Not sure what it is. Maybe I need a new sensor, maybe a new throttle body, not sure. The mechanic did say they cleaned a couple of the spark plugs, and said it could use a tuneup, but they said it wasn’t urgently needed. I don’t know if that’s causing this or what is. Hopefully I explained this well enough. Any help ASAP would be greatly appreciated, so I can either fix it myself or take it back to my mechanic to get it fixed. Thank you in advance for any assistance.

I included a picture of my dash with all the lights that came on. As you can see, no “check engine” or “service engine soon” light is on.

Welcome back to 2CarPros. A common cause for this is the throttle position sensor on the throttle body. They start to act up but don't throw a code because the problem fixes itself so fast. First thing is to check the connector to it. They can get corroded inside and send odd readings. Next would be to watch the signal output on a scope and see if any drop out appear. Or just replace it and save the diagnostic work. A set of plugs wouldn't be a bad thing if they haven't been done in a while.

The first time it went into fail I was going 65 with cruise control on. Cruise went off and ABS light came on. A couple minutes later it went into fail mode with no change in engine performance. Than service engine light came on. I drove an additional 60 miles home. The next morning no warning lights, and drove a few miles and again fail mode. I checked the computer codes and got one code P2106, which indicated throttle actuator control system. I reset the computer and drove several days with no problems. I called two ford dealers and was told the in the fail safe mode the vehicle should have performance reduction. Yesterday while in a parking lot the fail mode once again appeared with no service engine light. Restarted engine and everything OK. Any ideas?

thanks

Hey Ron,

Ford should know this one, this is a Tech bulliten from them:

WRENCH LIGHT ON WITH BOTH DTC P2106 AND P2135 - VEHICLES BUILT 11/29/2004 AND PRIOR

TECHNICAL SERVICE BULLETIN

Reference Number(s): 05-14-4, Date of Issue: July 25, 2005

FORD: 2003-2005 Thunderbird; 2005 Crown Victoria, Mustang; 2004-2005 Explorer, F-150; 2005 E-Series, Expedition, F-Super Duty LINCOLN:2003-2005 LS; 2005 Town Car, Navigator MERCURY:2005 Grand Marquis; 2004-2005 Mountaineer

ACTION

Replace the throttle position sensor (TPS) following the instruction sheet included in the TPS service kit. Reprogram the powertrain control module (PCM) to the latest calibration using WDS release B36.11 and higher, or B37.2 and higher. This new calibration is not included in the B37 CD. Calibration files are also available at www. Motorcraft.com

Please let us know what you find so it will help others.

Best, Ken

Hey Ron,

Ford should know this one, this is a Tech bulliten from them:

WRENCH LIGHT ON WITH BOTH DTC P2106 AND P2135 - VEHICLES BUILT 11/29/2004 AND PRIOR

TECHNICAL SERVICE BULLETIN

Reference Number(s): 05-14-4, Date of Issue: July 25, 2005

FORD: 2003-2005 Thunderbird; 2005 Crown Victoria, Mustang; 2004-2005 Explorer, F-150; 2005 E-Series, Expedition, F-Super Duty LINCOLN:2003-2005 LS; 2005 Town Car, Navigator MERCURY:2005 Grand Marquis; 2004-2005 Mountaineer

ACTION

Replace the throttle position sensor (TPS) following the instruction sheet included in the TPS service kit. Reprogram the powertrain control module (PCM) to the latest calibration using WDS release B36.11 and higher, or B37.2 and higher. This new calibration is not included in the B37 CD. Calibration files are also available at www. Motorcraft. Com

Please let us know what you find so it will help others.

Best, Ken

Yes, it is a drive-by-wire system. I have no accelerator pedal whatsoever when I turn the car to the arm position or started the throttle body you can hear it click three times but then nothing. I changed the actuator motor and I've changed the throttle positioning sensor. it has done this to me three times. the first time for three days the second time for a couple hours and then this time for 3 days now.

Hi,

Do you have diagnostic trouble codes? Also, have you checked the voltages at the accelerator pedal position sensor?

Let me know. I have the diagnostics for the APP if you need them. Also, if they exist, let me know what codes you have.

Take care,
Joe

Yes, the codes are p0122, p0223, p022, p2104, p2112, 6 p2110 and p2111. I know I do not have the voltage measurements for the accelerator pedal.

Wow, that's more than I thought. I went through each one. Rather than giving you a thousand page flow chart, here is where I suggest starting. It seems the codes center around the APP sensor and the TP voltages. So,that is where I would start. I attached the voltages at the APP sensor. Check that and let me know what you find.

If you want the flow chart, let me know.

Joe

My truck wouldn't start before. I took it to the dealership and they had to reset the anti theft system...now it wont accelerate over 20 mph

Hello,

This sounds like you have a dirty throttle bore causing the throttle actuator and pedal sensor to loose correlation causing the limp mode. Here is a video to help fix the problem

https://youtu.be/6fWYjfU9UV8

Please run down this guide and report back.

Thanks for this post I had this problem and fixed it by doing the service. I love this site.

I was having a problem with my o/d light flashing and my truck would kick out of over drive.So i replaced the speed sensor control and it ran fine for about two weeks. Then one day I went to the store and it would not go above 30mph. I was told it is in limp mode and have replaced the "TPC" sensor, the mass air intake sensor and replaced the O2 sensor and none of these have seemed to fix it. Please help!!!!!

first of all, you need to find out the code in the trans system it sounds like you have guessed up to this point hoping for a resolution.
once the code is pulled, the failure will have to be traced down to find out the real solution to the problem.

Roy

Okay so the initial codes were PO301 and PO306 we identified them as a misfire on cylinder 6 we changed all of the spark plugs and then the serpentine belt and pulleys due to a squeal that recently started but seemed unrelated. Now the squeal is still continuing and coming from underneath we think. But the SUV is stuck in limp mode and the last time I drove it a couple days ago it wouldn't go over 2,000 RPM's or 20 to 30 km an hour. We are totally stumped and could use some help. Thank you.

Would it be possible for you to upload a short clip of the noise? This would help tremendously! And have any new codes come up since the p0301,p0306? 2002 Explorer v8 doesn't have an electronic throttle body so I can't blame that. The PCM should have set a p1270 if it entered failure effects management mode. Were any coils replaced while the plugs were done? Also have a good look at the mass airflow sensor for any bugs or contaminants.

Codes p1131 and p1161 also popped up, but were cleared when spark plugs were changed. It's at my dad's house so I can't get a sound clip right now. I can in the morning.

Okay, those are lean codes and do not let a parts store sell you oxygen sensors for this! Lean codes plus lack of power = fuel pump or fuel system restriction or even a mass airflow sensor contamination problem. I would undo the air filter housing and inspect the mass airflow sensor, if it's contaminated you can give it a shot of brake clean or mass airflow sensor cleaner until the bug or whatever is stuck in it is gone.

Thanks so much! I will pass this info along and hopefully it helps!

No problem!