Even more god stuff.

I also had to clean the e-brake lamp switch contacts, but just because the lamp wasn't coming on.

FYI: That e-brake switch not making contact to light the lamp or, I think, a burnt out indicator bulb
will not allow a manual trans truck to automatically go into high idle.

 

Yep. Easy peazy.

See the attached document for explanation. Figure C1 shows how to use a switch to send 12v to the PCM AND operate a solenoid for the actual PTO solenoid. For those that aren't aware....a PTO is a Power Take Off device that is typically bolted to the side of the transmission. Modern units have a drive gear that is in full time mesh with the transmission gear (so it turns whenever the engine is running). The PTO drive gear has a clutch that connects it to the device (normally a hydraulic pump). That clutch is hydraulically activated via an solenoid valve. The solenoid is plumbed into the test ports on the side of the transmission so when power is applied to the solenoid, it sends hydraulic pressure to the PTO clutch and the PTO engages.

At idle speed the PTO doesn't have enough power to generate the required psi to operate most devices so the idle speed needs to be increased. Also, it's not good for the transmission because the fluid gets hot while trying to keep the PTO engaged at idle. So, Ford provided a wire that the body builder can signal the PCM that it needs more rpms. That wire is the one we are talking about. When the 12v is provided to the PCM via this wire then the idle speed increases. The PCM might also lock the TC but I am not certain (I'll check that with my AE next time I am using one of those trucks...). Maybe Mark K will see this thread and offer his thoughts about if the PCM locks the TC when in PTO mode.

Figure C2 is for older PTO systems that are manually engaged. So, the user would engage the PTO with a shifter or cable (similar to the 4x4 shifter on the floorboard). For those systems you only need a switch to fast idle the engine so this is what most of us are interested in as well.

Figure C2 is what you need. Skip the light. It's a nuisance anyway...

 

Correct. That same issue will not allow the PTO circuit to fast idle either. So, this switch I am talking about will only work if the parking brake is set (with lamp illuminated), IVS at idle and brake lights not illuminating.

 

Alright Shake-n-Bake, I found the Lt. blue w/ Yellow wire applied the parking brake and then applied 12 volts to check and make sure it was working before I wired the switch and nothing happened. Am I doing something wrong? I even went and bought a new switch and installed. Not realizing it was such a simple switch I could have cleaned it There goes $16 bucks.

Oh well I guess I have an extra that I will never use.

 

Sounds correct to me. Are you on stock(PCM) calibration?
As far as I know the only conditions are that the parking brake needs to be set and you can't have your foot on the throttle or on the brakes. Oh yeah, the transmission needs to be in park as well.

Maybe some PCM calibrations don't have the programing for the PTO active signal?
I tried this on my F250 and it worked so I presume it works for all PCM codes but maybe not?

 

I didn't even think about that. I do have a burn from dp on my stock PCM, maybe that is what is throwing it off?? If that is the case I am not happy about that, it is winter and I could use the high idle.

 

I have no idea if the DP reburn has anything to do with it or not.
I have a PHP tuner on one of my trucks, when I get home later this week I'll try it on that one and see if it works.

 

Alright thanks. I am going to email Jody and see if it should effect it like that.

 

I also cannot make it work, my pcm is stock and the park brake light illuminates, I'm in park, and the brake lights are off, is there any other conditions that need to be met?

 

Well maybe that is not only me then.

 

I appologize for starting a thread and not sticking with it. It got a little busy and I finally got a chance to try this out today. I found both light blue wires with a yellow strip. I tried supplying 12v to each wire seperatly to no avail. As far as i know i have a stock PCM but it does have a bully dog hard chip, i don't see how that would keep it from working. I will dig around some more and see if maybe i can find the 3rd blue with a yellow strip. If anyone finds a solution please let us know.

 

Alright got an email back from Jody and he said the burn would not mess up anything like that, so I guess I am one of the unlucky ones that it doesn't work on.

 

wow if this works that wold be great, do you think it would cause any problems with a remote start on the vehicle?

 

Looking at the picture, has me wondering. Do we need to connect two of the light blue wires with a butt connector and then try adding a 12v power supply? I am wondering if this is why we can't seem to get this to work.

 

I am not sure. I hope shake-n-bake takes a look at the thread and pipes up. I really would like to get this to work. It the pic it does say non OEM controls though, so I don't know.