Mustang 2012 loses power - dealer couldn't fix it
09-22-2017, 11:51 AM
#1
Thread Starter
Join Date: Sep 2017
Location: Bayern
Posts: 4
Mustang 2012 loses power - dealer couldn't fix it
Hello guys.
I have a huge problem.
I have a Ford Mustang 2012 V6 automatic.
After a car wash 5 weeks ago, I suddenly lost power during driving. Eventhough
I pressed on the gas pedal, the car didn't go any faster, but the RPM increased.
After a restart, it ran fine again for 4 days. Then the whole problems started.
Since then, I had the problem everyday. Sometimes it happens after driving 20 minutes,
somtimes it happens right away after driving out of my garage. I am not sure if the
car wash had anything to do with it or if it was the very hot weather that day that
triggered it the first time.
The first time the problem occured, the limp home mode light showed up. But this was
only once. After the restart, it was gone forever. I remember that the speedometer
needle sometimes bounced around when the problem occured or that it stayed at zero
even when I was driving. Also, one time when I tried to turn off the AC, it took 5
seconds before it reacted.
If the problem occurs in "drive" and I move into "reverse", the car doesn't move a bit
and only the RPM increases. After a restart, the "reverse" works. At least so much that
I can drive a few meters in reverse mode. So everytime the problem shows up and I try
to drive reverse, I have to restart the car before the swap from D to R works.
Anyways. I just got the car back from my dealer. The error codes showed that the
molded lead frame had to be replaced. It was done. I waited 2 weeks and thought
that the car finally works again.
But when I was drving home, the problem came again. I restarted, and I made it back
home without it showing up again. It seems that the molded lead frame swap didn't do
anything.
I cleaned the MAF-sensor and the Throttle Body. Nothing changed. I think I may have
****ed something up when I washed my car. I washed it from the front and I think that
water may have went into the engine. Maybe ignition plugs got wet?
My dealer said there is nothing he can really do. He also said that ignition etc. could
not be the reason as there would be lights on and so on. But I do not think that.
I hope someone here can help me out.
I have a huge problem.
I have a Ford Mustang 2012 V6 automatic.
After a car wash 5 weeks ago, I suddenly lost power during driving. Eventhough
I pressed on the gas pedal, the car didn't go any faster, but the RPM increased.
After a restart, it ran fine again for 4 days. Then the whole problems started.
Since then, I had the problem everyday. Sometimes it happens after driving 20 minutes,
somtimes it happens right away after driving out of my garage. I am not sure if the
car wash had anything to do with it or if it was the very hot weather that day that
triggered it the first time.
The first time the problem occured, the limp home mode light showed up. But this was
only once. After the restart, it was gone forever. I remember that the speedometer
needle sometimes bounced around when the problem occured or that it stayed at zero
even when I was driving. Also, one time when I tried to turn off the AC, it took 5
seconds before it reacted.
If the problem occurs in "drive" and I move into "reverse", the car doesn't move a bit
and only the RPM increases. After a restart, the "reverse" works. At least so much that
I can drive a few meters in reverse mode. So everytime the problem shows up and I try
to drive reverse, I have to restart the car before the swap from D to R works.
Anyways. I just got the car back from my dealer. The error codes showed that the
molded lead frame had to be replaced. It was done. I waited 2 weeks and thought
that the car finally works again.
But when I was drving home, the problem came again. I restarted, and I made it back
home without it showing up again. It seems that the molded lead frame swap didn't do
anything.
I cleaned the MAF-sensor and the Throttle Body. Nothing changed. I think I may have
****ed something up when I washed my car. I washed it from the front and I think that
water may have went into the engine. Maybe ignition plugs got wet?
My dealer said there is nothing he can really do. He also said that ignition etc. could
not be the reason as there would be lights on and so on. But I do not think that.
I hope someone here can help me out.
09-22-2017, 05:55 PM
#2
3rd Gear Member
Join Date: Jan 2007
Location: Acworth, GA
Posts: 648
Did you wash under the hood?
Have you pulled the negative battery cable and let the car sit for minutes or even an hour before connecting the negative ground back to the battery?
Sure am sorry about your problems.
Have you pulled the negative battery cable and let the car sit for minutes or even an hour before connecting the negative ground back to the battery?
Sure am sorry about your problems.
09-22-2017, 05:58 PM
#3
Thread Starter
Join Date: Sep 2017
Location: Bayern
Posts: 4
Hello Barry!
Yes I have disconnected the (-) cable for 30 minutes. I didn't wash under
the hood, but I used a power washer and cleaned the lower front of the car
which may have lead to water getting under the hood.
Following codes have been shown up:
P01288
P01703
P1780
The last code had something to do with the transmission problem that they have fixed.
The first code is a problem with the cylinder head temp sensor.
I have told my dealer that the problem seems to occur more often
when it is hot outside. But he ignored that. The problem never occured
when it is cold or in the evening at lower temperatures.
Could it be the reason it loses power and goes into limp mode?
Where is it located in a Mustang 2012? Or is it the thermostat perhaps?
Yes I have disconnected the (-) cable for 30 minutes. I didn't wash under
the hood, but I used a power washer and cleaned the lower front of the car
which may have lead to water getting under the hood.
Following codes have been shown up:
P01288
P01703
P1780
The last code had something to do with the transmission problem that they have fixed.
The first code is a problem with the cylinder head temp sensor.
I have told my dealer that the problem seems to occur more often
when it is hot outside. But he ignored that. The problem never occured
when it is cold or in the evening at lower temperatures.
Could it be the reason it loses power and goes into limp mode?
Where is it located in a Mustang 2012? Or is it the thermostat perhaps?
09-22-2017, 06:35 PM
#4
3rd Gear Member
Join Date: Jan 2007
Location: Acworth, GA
Posts: 648
For us 05 to 09 guys, when the Smart Junction Box gets wet, things go to pot.
Have you checked the passenger floorboard carpet at the side wall for moisture?
Do your rear lights all work?
Do you park outside or under trees a lot?
Have you checked the passenger floorboard carpet at the side wall for moisture?
Do your rear lights all work?
Do you park outside or under trees a lot?
09-22-2017, 07:06 PM
#6
Thread Starter
Join Date: Sep 2017
Location: Bayern
Posts: 4
I bought the Mustang in 2015. It was a rarely used car from a US soldier who
was working here in a US base in Germany. Only had 5k miles on it.
I park in the garage most of the time. There were no modifications at all.
I have just checked it. Thansk for the info. There is no moisture.
I have suspected that I may have ruined the electronics in the smart junction box, too.
The weird thing is that the car can drive perfectly fine for 20 mins. But
sometimes the problem happens right after I leave my home. I suspect
that it depends on the weather. The problem never happened at cold
temperatures.
was working here in a US base in Germany. Only had 5k miles on it.
I park in the garage most of the time. There were no modifications at all.
I have just checked it. Thansk for the info. There is no moisture.
I have suspected that I may have ruined the electronics in the smart junction box, too.
The weird thing is that the car can drive perfectly fine for 20 mins. But
sometimes the problem happens right after I leave my home. I suspect
that it depends on the weather. The problem never happened at cold
temperatures.
09-22-2017, 08:26 PM
#8
3rd Gear Member
Join Date: Jan 2007
Location: Acworth, GA
Posts: 648
Did a little more research. P1780 could be the Smart Junction Box
I would get some blue shop paper towels. Stuff them all around the Smart Junction Box
Wash your car like crazy with the water hose just like you did when the problem started
Check the paper towels for moisture. Shows up so much better on the blue over white ones.
I would get some blue shop paper towels. Stuff them all around the Smart Junction Box
Wash your car like crazy with the water hose just like you did when the problem started
Check the paper towels for moisture. Shows up so much better on the blue over white ones.
09-23-2017, 09:32 AM
#9
Thread Starter
Join Date: Sep 2017
Location: Bayern
Posts: 4
Hey Barry!
I did the thing with the paper towels. Indeed there was moisture. So probably something got wet when I first washed the car aswell. So most likely some electronic
problem. I re-seat the fuses in the SJB.
I also have some news. The car drove perfectly fine for 10 miles. Then after my car was in the sun for a few hours on my back home, the problem came again. Very weird
shifting and jumpy speedo needle.
Now I have found following post by a guy that had a similar issue like me with his truck:
Where is the ECU/PCM located in my Mustang 2012? I would like to check the wires by
myself that lead to the transmission. This could definately be a problem. I also washed the area below my wheels with a brush so I may have made something loose?
Thanks for the help by the way! Appreciated!
I did the thing with the paper towels. Indeed there was moisture. So probably something got wet when I first washed the car aswell. So most likely some electronic
problem. I re-seat the fuses in the SJB.
I also have some news. The car drove perfectly fine for 10 miles. Then after my car was in the sun for a few hours on my back home, the problem came again. Very weird
shifting and jumpy speedo needle.
Now I have found following post by a guy that had a similar issue like me with his truck:
It is fixed!! It was not the speed sensor and transmission lead frame, though both parts were replaced during the first visit. The root of the problem was the wiring harness that goes from the PCM to the transmission on the passenger side. This harness is wrapped in aluminum foil and it is held by a couple of clips attached to the firewall. One of the clips was either loose or just fell off causing the harness to touch the passenger's side manifold. As the harness touches the hot manifold after the engine has been running for a while, it would cause the PCM to go out of whack as well as the speed sensor and caused the transmission to shift erratically as well as the jumpy speedo. It was great because I got to ride with my ford mechanic who was watching the symptoms thru his ford ids laptop attached to my truck's obd port. The error code was always P1500, however as we drove, he could see the speed sensor loose the signal randomly as we test drove the truck. He then installed a new clip and secure the wiring harness and the jumpy speedo needle and erratic Trans shifting are thankfully gone!!! Now I can enjoy my supercharged truck!! Thank God
myself that lead to the transmission. This could definately be a problem. I also washed the area below my wheels with a brush so I may have made something loose?
Thanks for the help by the way! Appreciated!
09-23-2017, 08:41 PM
#10
3rd Gear Member
Join Date: Jan 2007
Location: Acworth, GA
Posts: 648
More than happy to help.
Funny thing, my 2007 was special ordered. When the dealer called we got to inspect it before closing the deal. I took blue shop paper towels and looked high and low for any moisture in the passenger floorboard. That was '07. Hard to believe 5 years later Ford hadn't cured the problem.
Funny thing, my 2007 was special ordered. When the dealer called we got to inspect it before closing the deal. I took blue shop paper towels and looked high and low for any moisture in the passenger floorboard. That was '07. Hard to believe 5 years later Ford hadn't cured the problem.