DodgeIntrepid.Net Forums banner

1 - 20 of 38 Posts

·
Registered
Joined
·
106 Posts
Discussion Starter #1
The light in the dash comes on indicating the cruise control has been turned on.

Once I hit the set button and let off the gas pedal, the car just starts slowing down.

I checked the plunger at the brake pedal and it looks ok to me, I tried recalibrating it like I found on here to do... but it still doesn't work.

Any ideas? (2002 300M)
 

·
Registered
Joined
·
555 Posts
check the vacuum lines on the servo if you have a vacuum leak there will be no cruise or maybe even the diaphragm in the servo itself has a leak you may have to change the servo but I'd check the vacuum lines 1st
 

·
Registered
Joined
·
106 Posts
Discussion Starter #4
check the vacuum lines on the servo if you have a vacuum leak there will be no cruise or maybe even the diaphragm in the servo itself has a leak you may have to change the servo but I'd check the vacuum lines 1st
Where under the hood is this located?
 

·
Registered
Joined
·
555 Posts
the cruise control servo is located right next to where you fill the windshield washer fluid at.

In the picture below the cruise control servo is circled as is the vacuum hose connection on 3.2/3.5 engines 2.7 will be in a similar location should be easy to find just follow the vacuum hose from the servo check the plastic hose and the rubber connections for cracks and dry rot if you have a vacuum leak it will not work

 

·
Registered
Joined
·
106 Posts
Discussion Starter #7
All lines look good, they're connected and no cracks or holes.

Could I do a short quick test of taping the plunger button down and see if the cruise engages?
 

·
Registered
Joined
·
106 Posts
Discussion Starter #9
Yeah, I don't think it's too serious.

I want to take this puppy out on a nice highway drive when I have to go out of town. She'll be sitting at home if I don't get the cruise fixed.
 

·
Woober Goobers!
Joined
·
50,299 Posts
Have you checked to see if the Cruise Control cable is actually connected to the throttle body?
 

·
Registered
Joined
·
106 Posts
Discussion Starter #12
Have you checked to see if the Cruise Control cable is actually connected to the throttle body?
From what I can tell in that tight space yup. Everything looks connected.

Ziptrix: thanks bud! I checked that t-connection first and it all looked good.

I'm thinking something is up with that pedal switch.
 

·
Registered
Joined
·
106 Posts
Discussion Starter #13 (Edited)
Ok so the t-connector is solid, the lines all look good. The cable is attached to the TB like it should.

I can turn on and off the cruise control light all I want. So those buttons work. On one run, when I hit the accelerate button on the other side the cruise light went off and wouldn't come back on till I shut the car off and started it again. Weird.

I pulled the pedal out to make sure it was clicking that button in, it seems ok but next I'm going to try taping the button down and do a short run to see if it engages when I try to set it.

Could be vacuum related elsewhere? The car while in gear and stopped, has a shudder/vibration. The RPMs don't fluctuate or anything but to me it reminds me of a vacuum leak.

At first I thought it was bad gas because I bought this car and it hasn't ran in quite some time, I added a fuel injector cleaner to what was in there and burned that half tank and tonight she got a fresh full tank with another injector cleaner. The shudder is still kinda there.

edit: if you have the cruise on, and you hit the brake - isn't the light supposed to go off in the dash? If anyone can tell me this, it would really narrow it down I think.
 

·
Registered
Joined
·
106 Posts
Discussion Starter #16 (Edited)
I think my servo is toast.

All the lines are getting good vacuum when I disconnect from the plenum, with the car running and unplugging the vacuum line going right into the top of the servo - there's good suction.

I could check the harness underneath, what sort of voltage should it be getting?
 

·
Registered
Joined
·
631 Posts
It could be the actual SET switch is shot. Have you tried checking for stored codes? From what I have read, the CEL does not always come on when there is an issue with the cruise control and need DRB3. I'm not positive, just what I read.
 

·
Registered
Joined
·
93 Posts
Other than than resesting the plunger on the brake light switch, did you also check the continuty of the switch terminal's for the cruise control to see that they are changing state from N.C. to N.O. and vise versa. There are 3 different sets of contact's in the switch terminals 1&2 and 3&4 control cruise control, and 5&6 are for the brake lamp.
 

·
Registered
Joined
·
106 Posts
Discussion Starter #19 (Edited)
Ok so I swapped in a different servo and it's the same deal. Checked all the cable connections, everything is good.

So now I'm going to focus more on the steering wheel switch or the brake switch. Or figure out how to check the harness connecting to the servo, make sure it's sending a signal.

There's no codes related to cruise control in the car.
 

·
Registered
Joined
·
93 Posts
I've got my money on the brake light switch. It has been the biggest reason of non-operitive cruise controls I've seen, either from being out of adjustment or just having bad/worn contacts. You can get get the brake switch's most places for about $15-20. Otherwise use an Ohm meter and check for different resistance values of each of the crusie switches by pressing one at a time. I would start at the clock spring connector (RD/LG & BK/LB wires) and work down line to the PCM.
 
1 - 20 of 38 Posts
Top