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sprinkles08
sprinkles08, Chrysler/Dodge/Jeep master tech
Category: Dodge
Satisfied Customers: 22830
Experience:  ASE Master and Advanced Certified, Chrysler/Dodge/Jeep Master Certified, Trans and Hybrid Specialist
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2007 Dodge Caravan: 3.3L v6the cruise control..light comes..overdrive

Customer Question

2007 Dodge Caravan, 3.3L V6

The cruise control is inoperative. The "CRUISE" light comes on and goes out when I press the button, but nothing happens when I press "SET". If I press and hold "ACCEL RESUME", the car will downshift out of overdrive. Releasing the button will allow the car to go back into overdrive. The "CRUISE" light will then go off, and pressing the button will not light it back.

I suspect the cruise control module (CCM) is fried, and I will need to replace it. I've heard that a bad CCM will throw a code to the computer, but will not light the Check Engine light because this code is not emissions related.

Any ideas? Where is the CCM if it needs to be replaced?
Submitted: 6 years ago.
Category: Dodge
Expert:  sprinkles08 replied 6 years ago.

Hello and welcome to JustAnswer!

 

Let's see if any fault codes are stored. Cycle the key from off to on three times ending with it on and watch the digital odometer display. Don't crank the starter, just off to on. The codes start with a P and have four numbers, there may be more than one stored. Write down any that you see and post them here.

 

 

Customer: replied 6 years ago.
P0441
Expert:  sprinkles08 replied 6 years ago.

That one wouldn't be related I'm afraid. Is that the only one you saw before it said "done"?

 

 

Customer: replied 6 years ago.
Nope. I walked away too soon! There's also P0594.
Expert:  sprinkles08 replied 6 years ago.

Great! That one is related.

 

Do you have a voltmeter or test light to do some electrical testing, or are you more looking for some possible causes?

 

 

Customer: replied 6 years ago.

I have one, but I won't be able to do any testing until the morning. The "boss" just took the van to work.

 

If you can explain any possible causes in the meantime, that would be OK as well.

Expert:  sprinkles08 replied 6 years ago.

The cruise control is controlled by the cruise servo. This is mounted just to the right of the battery tray. It has an electrical connector, one vacuum line, and a cable that runs up to the throttle body to open the throttle.

 

The P0594 sets when the powertrain control module (PCM) detects that there is no power at the cruise servo when there should be. Power is supplied to the cruise servo through the brake lamp switch which is mounted under the dash on the pedal bracket. The servo is powered when the brake isn't pressed, but then power is lost when the brake is pressed.

 

This could either be a problem in the wiring to the brake switch, from the brake switch to the servo, or it could be the brake switch itself. It's pretty likely to be the brake switch, which is a cheap and easy repair.

Customer: replied 6 years ago.

What kind of electrical testing should I do in the morning?

Expert:  sprinkles08 replied 6 years ago.

You'll need to check for power at the cruise servo first. With the engine running press and hold the cruise On button and check for power on the violet/white wire at the cruise servo connector.

 

If there is nothing there (there shouldn't be) then you would need to go to the brake switch under the dash. Again press and hold the button and check for power on the violet/white wire. If there is nothing, press and hold the cruise button and check for power on the violet/yellow wire. Most likely you will find this is ok, but there is nothing leaving the switch on the violet/white wire, and the brake switch will need to be replaced.

Customer: replied 6 years ago.

I have the switch out, and I ohm-checked it. It has six blade-style contacts in a row: 1-2, 3-4, 5-6

 

Well, with the plunger pushed in, it reads:

  • 1-2, open
  • 3-4, closed
  • 5-6, closed

With the plunger out, it reads:

  • 1-2, closed
  • 3-4, open
  • 5-6, open

My guess is 1-2 controls the brake lights because pushing the brake pushes the plunger out (just checked it out; I jumpered the pins at the connector and the brake lights lit). So it seems the switch is working. Maybe by taking it out and jiggling it, something has broken loose. So I'm going to road test and see what happens.

Expert:  sprinkles08 replied 6 years ago.
Taking the switch out may have definitely masked the problem, which is why we needed to check for power at the servo first. If we had none then we would have gone to the switch and checked for power there, by backprobing in the switch connector so as not to disturb anything.

Make sure the brake lamps still work ok when pressing the brake, then go ahead and take it for a ride and see if the cruise does work now.
Customer: replied 6 years ago.
Sorry for not replying sooner, but I am away from home working and I won't be back until the weekend. I'll do some voltage checks then.
Expert:  sprinkles08 replied 6 years ago.

Sounds great! Let me know what you find and we'll take it from there!