Clock Spring / Spiral Cable Going Out?

2008 DCSB 4x4 (auto) with about 156k miles.

For a few months, I've had an intermittent cruise control. Both the cruise control indicator light on the dash and the cruise itself will not work for the entire trip, but it *sometimes* will work again if the temperature changes or the truck sits for a while, or a breathe correctly, or something....? Its super random.

I've tested the horn, radio, and other items when this happens, and the cruise appears to be the ONLY item that goes in and out. All other things like steering wheel audio controls, etc...all work fine regardless of what the cruise is doing. No CEL and no airbag indicator lights are currently showing up, either.

Is this for sure a spiral cable/clock spring problem, or is it possible that its something else? I'd like to explore potentially cheaper fixes before dropping $200 on a new Dorman clock spring and/or if I do spend $$$, I'd like to fix the actual problem.

Edit: After further research, the problem would likely be a fuse or the actual cruise control switch. I'll check both of those tonight after work.

 

Sorry I can't help with this part but if you can find a wiring schematic for the cruise and possibly a diag. flow chart those 2 things will be invaluable in diagnosing this correctly. Instead of just taking WAGs or others doing the same. Also there is a possibility that there are some stored fault codes which would help if you could get the dealer or someone to scan the truck (and not just the powertrain) and pull codes from all the systems that might show some information on where to start.

 

Its not a "for sure".
It could be ANY component from switches, wires, ecu.

You can get ebay spiral cable new (knockoff) for about $10.

 

Thought about going that route, but the more I look into this, the more I think its the cruise switch. It feels a little different when I push the On/Off switch than it did before. I'm thinking about getting a replacement switch and see if that solves my problems. Or biting the bullet and buying a more advanced OBD2 scanner to see if I can dig into the ECU readings.

 

Note that the ECU will NOT tell you if the switch or wire is bad.

If it were me, I'd test the switch (and spiral cable) before committing to replacement.
The cruise control switch has TWO wires going into it. One goes to chassis negative, and the other goes to the engine control module.

The wire that goes to the ECM is set INPUT PULL-UP. What that means, is that it will be carrying some fixed voltage through a resistor. The ECM will be monitoring the voltage on that wire, and when it sees the voltage drop to certain pre-determined values, it will understand that as "button pressed". Each of the 4 buttons (on/off, +, -, cancel) will have a different voltage reading. The only one I can tell you right now is that the on/off button will have a voltage of "0" when pressed, but I can also tell you this; in order of increasing voltage, they will be on/off, +, -, cancel, none.

The reason I can't tell you the voltage for any button besides on/off is because the wiring diagram doesn't show any of the necessary values, such as input voltage, pull-up resistance, or the resistance of any of the resistors in the switch itself.

What you want to do is make sure that (1) the line from switch to CHASSIS NEGATIVE is solid, (2) the line from the ECM to the switch is solid (the wire color is BR-W). You can do all of this in one place as follows; identify which of the wires coming from the switch is to chassis negative (use your multimeter set on resistance/continuity and test the wire against chassis negative, look for 0 ohm resistance). Disregard that wire, take the OTHER wire and hook it to the RED wire of your multimeter. Take the BLACK wire of your multimeter and hook it to a well established point of chassis negative, if possible, AWAY from the steering wheel altogether. Set the multimeter to VOLTAGE with a range above 15 volts -- most will have a 20 volt setting, which would be ideal. Then you just watch the voltage as you are trying to use the cruise control. If it jumps around at all when you're NOT pressing buttons, then you have a break between the ECM and the attachment point. If it doesn't react or jumps around WHEN you are pressing buttons, then you have a problem between the attachment point and the switch's negative connection. Now just move the multimeter around until you isolate the exact point of failure.

 

The guy in this video is using a very expensive scanner tool, but he digs into the ECU and discovers the exact sequence that fails. Go to the 6:00min mark.

https://www.youtube.com/watch?v=D-wtB7xq2No

 

You're misunderstanding. Reading codes from the ECM can only tell you "if a button is pressed". It cannot tell you *what part is broken*. You may be able to extrapolate from it if one button works and another button does not, then the button module needs to be replaced. But if NO buttons work, then the failure point could be **anywhere** along the wire from the ECM to the ground point, including any component along the line. For example, a BAD GROUND cannot be detected by reading codes from the ECM, nor can a broken/intermittent spiral cable.

Also note that if it happens to be just the on/off switch that is failing, then you do NOT need to replace the switch. Because that particular button is a pull straight to negative, you can just put a momentary push button switch anywhere on the line from the ECM to the steering wheel to do the same job.

 

Did you watch the video? He goes through and finds out that the push/pull button is the exact part that's broken. So he replaced the entire stalk to fix it. Correct me if I'm wrong, but you're suggesting putting a random switch somewhere to engage my cruise control?

 

I'm not suggesting any particular form of repair. I'm suggesting that you COULD, *IF* that is the problem, and if you prefer to spend $0.30 on a generic button than whatever the cost of the cruise control lever happens to be.

And again let me reiterate: It is a TECHNICAL IMPOSSIBILITY to isolate a broken wire or spiral cable or bad ground by playing with computers.

 

Got it. I don't know enough about electrical components to argue about anything with intelligence, so I'll just take your word for it. But the program he's using shows various component values when he attempts to engage various functions on the stalk. Are you saying that the program is giving him false readings?

 

No. I'm not saying that its giving false readings. What it is doing is exactly what I said it does -- it can tell you if some button *IS* being pressed, and what button it happens to be -- but that's all. The problem with it is if the wire is broken, or the spiral cable, or the ground, then it won't show anything at all.

Using a multimeter hooked up the way I described, you can read the button presses, AND you can track the exact location of the fault.

 

I wanted to update this thread, because I have yet to solve my problem. But today it did something I haven't seen before.

I took a short trip out of town today, and of course it was a "bad day" for the cruise control. It wouldn't engage at all. Then for the return trip, the indicator light came on. I got excited that my trip would be better going home. But THIS time, the indicator light came on, but the cruise control wouldn't engage. Normally if the light comes on, the cruise will work fine for that entire trip. I tested the horn and radio controls several times during this episode, and all worked fine. Even more weird, the indicator light stayed ON the entire time, even when I tried to disengage the cruise on the stalk.

To be clear - I've never once had intermittent horn or radio controls - only the cruise.

I really think this problem is with the stalk itself.

 

Go buy a $20 multi meter and watch a youtube video on how to use it and test the cruise control switch like the 96cardboard said. If you cant figure it out your only out $20 and best case you save money by not just throwing parts at it and get your truck fixed.
Or if you have a really good freind with a Tacoma borrow their cruise control stalk.

 

Something is broken, and based on the symptoms, its likely either the clock spring or switch. So I'm definitely going to be spending some amount of money either way. Based on the symptoms, I've concluded that its probably the switch. Best case scenario is actually that I've narrowed it down correctly based on those symptoms, and that I purchase and replace the correct part without having to spend extra money.

My bet is that I could spend $30-40 on a decent multimeter, and all its going to do is confirm my suspicions. Then I'll have spent $130 to fix a $90 problem and disassembled my airbag twice instead of once.

That said, I appreciate the advice and will consider it before making my final decision!

 

WOW! Weird logic. It never occurred to you that you could use the multimeter to properly diagnose future problems, as well as your current problem?

 

He doesnt need a multi meter his cruise control is broke and he wants to know how to fix it without buying parts he doesnt need, because they aren't broke.

 

I've fixed nearly all the problems I've had with no need for one so far. As I said, I may buy one and do exactly what you're suggesting.

Not sure why you feel the need to be such a dick about it...

 

Are you recall eligible

 

Not being a dick. Just pointing out that a multimeter is the most valuable tool for diagnosing electrical problems and figuring out how circuits work. Something as simple as figuring which circuit to tap into for accessories becomes easy. But, if you want to roll the dice on a new stalk, go for it.

 

I know it *could* help in this case. I also know that I've never really needed one. So I'm debating whether this warrants finally getting one or not.