I have been trying to figure my cruise control not working. I verified the switch for the brake pedal and the one on the master cylinder are not the problem. I have read about the clock spring but would like to verify signal is passing through/ not before replacing.

2 Questions.

#1 I have is how does the overall system work? Ok not that in depth but, is there some kind of servo that regulates the flow to,the injectors or is it strictly controlled by the PCM? and it tell the injectors to open to allow fuel to pass.

#2 anybody have a wiring diagram for the cruise control control circuit. Namely looking to verify switches are working.

 

Its all in the pcm.
Best way to test is with a scan tool.

 

Cheezit is right on the testing.
I can post the diagram for you later tonight. And I'll see if I can get you the pinpoint test steps.
There may be some that don't need the IDS/VCM to do.

BTW the system is all electronic and not any servos. This is do to the drive by wire throttle we have.



Sean

6.0L Tech Folder

 

Do the horn, blinkers and hazard lights all work?

 

I have some Files for you.



Sean

6.0L Tech Folder

 

yes, the horn lights and blinkers all work

 

Thanks for the diagrams. That's exactly what i needed!

 

I've had the same problem as the OP, just haven't had time to do the entire test procedure. New switches in the steering wheel, new pressure sensor on the master cylinder, and a new clock spring (but for a different problem).

What scan tool aside from the dealer tool will diagnose cruise control problems?

 

You need something that will read the Ford PIDs
IDS/VCM will do it.
AE might not sure.
Some of the newer ones like Snap-On,Matco and Mac may. Have not
played with my new MODIS and I am not sure about my older SOLUS.
It needs software update and happens to be for sale

The local auto parts store scan tool most likely won't.



Sean

6.0L Tech Folder

 

I tried some of the diagnostics today with no luck . I am new to Diesel so here comes a stupid question. I tried OHMing the inputs of the switches like the document says. Im reading open on every test all switches? It dosnt seem right. I put sewing pins in the connector on both of the connectors on the PCM located right behind the driver side battery. Would that indicate the clock spring is defective? Early in the diagnostics it says to check fuses 10 and 34 in the battery junction box. If its referring to the fuse box under the hood there isn't a fuse 34 (10 is good), if its referring to the fuse box under the dash there isn't a fuse 10???

 

BJB is under the hood
CJB is in the cab.

Sounds like a bad clock spring.

You can check the column harness BUT remove the airbag
after you let it sit for a while so you don't trigger it. A meter has
enough power to set it off.

You can access the clock spring harness under the dash and then
see if you still have opens when checking it. They are not that hard
to replace. You will need a new bolt along with the clock spring for
your rig. Use you VIN number to order the part.

Good place for real Ford parts at a good price. >>> FICMRepair.com - FORD Powerstroke 6.0 FICM Repair, PHP Tuning and Truck Parts

I can post the PDF on how to do the change if you need me to. Just let
me know if you need me to.



Sean

6.0L Tech Folder

 

I think I would like to try verifying the connector under the dash before dealing with airbag/replace clock spring.

Can you tell me what connector has the clock spring harness and what pins the switches are on?

Assuming continuity check would be on that harness instead of resistance?

I don't have (at least not yet?) the diagnostic tool you mention above. Is that tool required to be connected for Ohm test to work?

 

The clock spring harness is what your going to be working on. STAY AYAY from the
yellow jacketed wires Up behind the air bag and the 2 wire connector under the
dash it's wires are Gray/Orange & Gray/White. The under dash connector has a metal
tab to act as a shorting bar when unplugged The connector body on mine is black with
only 2 pins and that shorting clip. The connector body of the one you want on mine
is gray and 8 pins.

NOYE : Set wheels straight ahead before starting. Clock spring only has so much extra
and if you turn past the length of the wire you will break it.



The shipping lock come out once your ready to put the wheel back in place so
you don't by accident turn the clock spring and break it.

In the 2nd photo off to the side of the spring is the key in trigger wire.
Remove of cut it and you will not get a key in buzzer. It works when grounded.


This one here is the part number I used in my truck that has all the controls.
Verify that you are ordering the correct part for yours.






Sean

6.0L Tech Folder

 

Just a thought from left field...have you checked that your break lights work? If the break lights are out, the cruise won't engage, I had that problem once, the third break light was out and cruise didn't work until it was replaced.

 

I ended up taking this to a repair shop that has a scan tool. I had a dtc pointing to the abs system, he tested the switches on the steering wheel, clutch pedal switch, brake pedal switch and the switch on the master cylinder as well. All these switches are working as well as the abs module replaced. Still no cruise control.

i needed the truck for a hunting trip to Canada. So I had to pick it up before repair shop figured it out. But, he said with no dtc appearing at all in the PCM, steering wheel switches working, clock spring ok, brake, clutch, and master cylinder switches good. He wasn't sure where to look next. After 18 hours each way with no cruise mt leg is sore as hell.

I saw the last post about the 3rd brake light and sure enough the bulb was blown. I thought I got it now....put in new bulb....crap still no cruise control.

What else could possible be causing this? Any help where to start would be greatly appreciated. I like the truck, but my leg can't take another trip like this last one...please help!