The first actual difficult minivan failure: Chrysler electrical content ahead. Help needed.

2011 Dodge Grand Caravan.

I sent it to the dealership for T33 recall, and now cruise control doesn't work.

Before, very occasionally, I had to hit the button more than once to get the cruise to turn on. I never thought about it at all.

I sent it back to the dealer, they said it was an intermittent switch. They gave me a quote of something stupid like $300. I was irritated, but could sort of buy an iffy  switch getting jostled around. I bought a real Mopar switch for $30 and put it on. Here is where it gets weird.

Install the switch, start the van, cruise comes on, then goes off and stops working. Pull it apart, leave the switch hanging so no wires are pinched, start the van, cruise comes on... then goes off.

Obviously there is something for-real intermittent. Obviously it isn't the switch. I didn't pay the dealer a dollar for the diagnosis, so I am willing to eat the switch cost, but I still have no cruise, and the connector and all wiring in the wheel appears perfect and I can't see any issues. Furthermore, it isn't really intermittent so much as it's always failing after a few minutes and never coming on again, regardless of jostling.

Now, I could go to the dealer and yell and hollar, but I am not sure they would even know what to do, other than some free lousy coffee.

Ideas?

Does it seem to matter what position the steering wheel is in?  For example does having the steering wheel turned or straight affect the cruise at all.  Curious if the clock spring could be at fault.  

If I am understanding your description correctly, it works after a key cycle.  So whatever module controls the cruise does its self check, the vehicle passes, then whatever the fault is shows up and the module shuts operation down.  This is where it would be nice to scan it with a WiTech to see if there are any "switch short to ground" type history codes.  

An intermittent issue like that always points to a bad ground for me. Is there a way to trace back the wiring to see where it goes? Especially if someone was working around the termination area of the connection point for the recall. 

In reply to logdog :

No, it only works when I physically unplug it and plug it back in. Then it turns on, but only for a bit. Short enough that I have not been able to actually engage the cruise while driving. After a key cycle it's still non functional.

Steering wheel position doesn't seem to matter.

In reply to mndsm :

Modern car like this, there are too many to count. There is more wiring within the steering wheel of the car than in my entire 72 GMC. The wiring is all virgin and perfect appearing, and also covered with a sweet fabric sheath everywhere with no visible indications of strife at all.

What is the t33 recal? what did they actually replace?

In reply to Robbie :

Checked and potentially added a sleeve in the wheel.

https://static.nhtsa.gov/odi/rcl/2017/RCLRPT-17V376-1532.PDF

I'm assuming it's this problem?

Based on how you said the wiring was fine around the clock spring and horn, does hitting the brakes normally kill power to the 2011 cruise controls?  On my 2005 (and every other vehicle I own), it should only turn off the active cruise, but cruise control is still on ready to be resumed.  Maybe try unplugging the brake connector?

I'm wondering whether instead of intermittent, it's the system's response to an intermittent switch being constantly "on"... As in a short somewhere between the switch and whatever it's wired to. Do you have access to check that? When you unplug it and plug it back in, I'm guessing that's at a connector close to the wheel?

• The fact that you can effect a "reset" of the current symptom by removing/reinstalling the switch suggests that the issue isn't between its connector and the brain... probably (I don't know whether this goes to a cruise module, the ECU, or what)
• The fact that you replaced the switch but it still does it suggests it isn't the switch (but just for giggles, did you check the new switch to make sure it's actually momentary?)

My gut (which does not have an EE) says it's the system's reaction to a momentary input getting a constant signal. The switch is "on", so it's turning, on, then recognizing that the constant signal doesn't make any sense, and shutting off. That is, admittedly, at odds with the fact that it doesn't happen per-cycle, but does happen if you remove and reinstall the switch. Of course, getting a second dud switch would reconcile those things, especially on a late vehicle where settings state is more likely to be captured even when it's "off".

*Sigh*. Yet another troubleshooting thread that's going to bug me 'til I find out what the resolution is.

In reply to WonkoTheSane :

It is not that problem. Once it shuts itself off, I cannot turn it back on other than unplugging the switch and plugging it back in. This makes pretty much no sense as far as normal computer logic goes.

Brake shuts off cruise. You may have something there. I'll try reconnecting the switch and driving somewhere without touching the brake pedal to see if it stays on. That will be a challenge.

In reply to Ransom :

The connector is -in- the wheel btw.

tuna55 said:

In reply to WonkoTheSane :

It is not that problem. Once it shuts itself off, I cannot turn it back on other than unplugging the switch and plugging it back in. This makes pretty much no sense as far as normal computer logic goes.

That depends on whether it's a true electromechanical switch or if there's some more electronics in there. Maybe the "switch" has something to "remember" it should be disabled, and unplugging it clears this through power-cycling.

The switch is possibly a variable resistor.  Is it an on/off switch, or the set/accel switch?  Momentary contact?  The ecu needs to see the right voltage from the switch, or it will shut stuff off. 

You need a scan tool to watch the data live.

In reply to Streetwiseguy :

Multiple on/off, but not sure on the arming switch, could be momentary and the ECU does the hold or the switch does the hold.

tuna55 said:

In reply to WonkoTheSane :

It is not that problem. Once it shuts itself off, I cannot turn it back on other than unplugging the switch and plugging it back in. This makes pretty much no sense as far as normal computer logic goes.

Brake shuts off cruise. You may have something there. I'll try reconnecting the switch and driving somewhere without touching the brake pedal to see if it stays on. That will be a challenge.

Ah, yeah, that's probably not related to the brakes then.  I like Ransom's idea.  

I'd pull out the switch (or check with the one you already have on the shelf) and use a meter to verify that the on/off switch is actually working correctly like a switch (continuity when on, no measurable contiunity when off).

Don't know if it will help, but the Forte had a weird thing where the cruise control would not turn on until the brake pedal has been depressed (switch activated). I might check there and work up. With it, the switch could activate the cruise without activating the lights. 

In reply to WonkoTheSane :

Might try. The thing has all of the pins, and they be tiny.

Sounds like the switch might indeed be an electronic control system. If it were an electromechanical switch, you'd expect the number of pins to be, at most, the number of buttons + 1.

Have you been in as deep as the dealer went to perform the recall? Sounds like a pretty straightforward situation to me,  you had a flaky switch, then they inadvertently screwed something up in there,  they went with the easy diagnosis when you complained. 

I'm not familiar with the Dodge Caravans specifically but that's new enough the I would expect a scan tool capable of reading manufacturer specific PIDs to be able to read the cruise control switches as well as the brake switch for the cruise.  I'd start there as knowing what the computer thinks its seeing would be helpful.

Scan tool.  Scan tool.  Scan tool.

If I remember correctly, the switch just talks to a body computer. 

The window switche module on the front doors had their own board integrated inside them. The cruise switch module may have a small board that is having interference with communication through wiring or the main body computer faulting. Thus it defaults to permanent off state.

When it is removed and reinstalled it tries to connect again when triggered and faults out to the safe mode.

Mine did the same thing, while they were doing the recall for that and the rear window switch they replaced it and it has worked 25,000 miles since. I’d say something else got messed up.

Bcm is flaking out. The newer vehicle switches run off variable resistance for each function. Either way, proper scan tool and diagnostics needs to happen.

I obviously have no access to real dealer-grade scanning tools.

Do I have a hope of this being caused by the dealer, or is it truly just a coincidence?