Does the computer on the 4.6 enter a 'forced limited power' state at any point due to high RPM - at or near redline in order to preserve engine/transmission components?

Thanks!

 

What make year? We can see this stuff through the Internet.

 

The PCM has a built in rev limiter (4500 rpms for the 4.6 as I recall), it also has a max speed programmed into the unit (my 2004 was at 108mph). It will not exceed a specific rpm when in neutral. My 2004 4.6 wouldn't rev over 1800 rpms when in neutral. My current rig has the 3.7 and it cuts it off at 3000 rpms when in neutral. Not all years have the same parameters but yes, the engine has programming in it help it live while a dimwit is in control.

 

I think it's 5400, not 4500.

 

I think you'll find the numbers for the 3V engine were 5700 rpms. The 2V engine I had, per old pics that I found, the redline on the tach is 4800 rpms. I'm remembering chatting with one of the Ford trouble shooters back then and he talked about the 2V rods would only handle up to 5000 rpms and then it was iffy at best. Considering the OP hasn't come back to this post, I guess we'll never know what his engine is......or maybe he doesn't know.

 

Hi,
It's actually a 2006 out of a Crown Vic Police version. When it revs up high under throttle, it will suddenly loose power and sometimes sets the code 'Forced Limited Power". I am wondering if it hits redline or above and the computer reduces the power to spare the engine/torque converter...

Thanks!

 

Assuming you are talking while the engine is under full acceleration, in gear, and the car is moving and you get this code at close to max rpms. There is a malfunction somewhere. It can be as simple and stupid as a bad radiator cap and as rare as a failed throttle actuator. It can be a bad thermostat, EGR malfunction, ABS issue, etc. But something somewhere in the car there is a problem that basically is setting the PCM in the limp mode. Since you didn't list any specific codes, I assume you don't have any other codes?

 

Hi,

Thanks kindly for you reply!

You are correct, the engine is under full acceleration, in gear, near (I think) max RPM. The codes returned vary a bit, but 720, 2107 sometimes, and108 are coming up. Would be really nice to get a handle on this.

Thanks in advance for your help!

Dan.

 

https://www.obd-codes.com/p0720

https://www.obd-codes.com/p2107

https://www.obd-codes.com/p0108