nickg

on a GM 6.5 diesel the PTO wire is either powered up or grounded out and it causes a fast idle, so this might work on a dodge, something to look at for sure

on a 2003 CTD and up all you need is to turn cruise on, hit set, then use the accel/decel buttons to set desired RPM, P-brake does NOT need to be set, if you touch the brake or accel pedal it will turn the hi-idle off, this feature has to be enabled at the dealer though

bakdoor

Read this thread, had to try it! It does not work on a 2002 with a 5 speed. I tried both using the "accel" button to bring the idle up, using both "set" and "accel" together, and I tried bringing the idle up with the pedal and using the "set" or "accel" button, it always goes back to base idle. Nice idea though.

I like the hand throttle idea, cheap and effective, use one in my Jeep for running the on-board air.

dakar

it's worked on my '01 for a long while now.... had the program turned on at a dealer 6-7 years ago.

cowboykilla235

at what temps does it work at for you?

dakar

Seems it used to work at any temp, before moving down south, although I tried it earlier this afternoon at 85F and it would not engage the throttle

KATOOM

I remember this topic being discussed years ago on another forum and if I remember right, the 2nd gen ECM isn't set up to allow high idle changes via the cruise control buttons. BUT.....there is a designated ECM wire for the PTO high idle which lays unused. By tapping into that wire with a switch, I think I remember it causing a high idle feature of about 1200 RPM for PTO usage. So some guys tapped into this wire and achieved a high idle feature at the flip of a switch. This is NOT the 3 cylinder high idle either.

DragonSlayer

I would love to get a high idle setting on mine, you know how to find that pto wire?

KATOOM

I'll see if I can find out more info on it but if I remember right, I think its running along the top of the firewall and is even marked.

linetrash75

I've seen the wire labeled pto never messed with it though.

KATOOM

Well dont quote me since I'm shooting from the hip here trying to remember back about 7 years.....so try this at your own risk. I think if that wire is grounded, it will cause the idle to raise to about 1200 RPM. It should be a wire that goes nowhere too.

AggieJustin

Here's the info on the PTO wire from the '01 FSM.

It's in the ECM connector on Pin #26. It is an 18 gauge Orange wire. This goes up to Pin #2 on Connector C125 which is on the firewall (shown here).



C125 should be a black connector, where C126 right next to it is gray.

Unfortunately, the wiring diagram doesn't say whether the pin should be grounded or have voltage applied to it. It only shows the PTO Switch Sense as the end component.

kreynolds

FWIW, here is a similar thread from cumminsforum from last year.

This is quoted from my 01 FSM, section 14 page 48:

PTO SWITCH
DESCRIPTION
This Powertrain Control Module (PCM) input is
used only on models equipped with aftermarket
Power Take Off (PTO) units.
OPERATION
The input is used only to tell the PCM that the
PTO has been engaged. The PCM will disable (temporarily
shut down) certain OBD II diagnostic trouble
codes when the PTO is engaged.
When the aftermarket PTO switch has been
engaged, a 12V + signal is sent through circuit G113
to PCM pin A13. The PCM will then sense and determine
that the PTO has been activated.

On my truck, the orange wire marked PTO doesn't terminate in a connector. It hangs out of a wire loom at the top of the firewall. It sticks out dead center over the motor.

AggieJustin

That is the description for the gasoline engine and PCM. The description of the PTO switch for the diesel engine with the ECM is on page 14-104.

PTO SWITCH
OPERATION
This Engine Control Module (ECM) input is used only on models equipped with aftermarket Power Take Off (PTO) units.

The input is used to tell the ECM that the PTO has been engaged. When engaged, the ECM will disable certain OBD II functions until the PTO has been turned off.

I'll have to go outside later and take a look at mine. Right now I'm only going off of what the FSM wiring diagram is telling me. I'll have to confirm it under the hood later.

kreynolds

You are correct. I sometimes struggle reading my FSM because its in pdf format. thanks

I've been doing some searching on this and all of the posts say to ground the wire. My searching however has not turned up any verification that this trick works.

AggieJustin

I hit the same problem in the wiring diagrams since they have almost identical layouts save for a couple of wires, but they're on different pages.

Grounding seems to make the most sense, but based on that post from CF, it sounds like this is only to tell the ECM to shut off certain codes. Just not sure what kind of codes would be set. I guess it depends on what method you're using to ramp up the idle.