Headlights Cause Cruise Control Failure (1 Viewer)

[deeptide]

1998, 100 Series Land Cruiser - 100% OEM/Stock - No after market wiring

I hesitate posting this question because it 'sounds' like (to my limited experience), "How do I set my laser printer to stun?" , but this is real .

I'm curious if anyone knows why cruise control would immediately fail when headlights are turned on ? The "cruise" dash indicator blinks immediately after failure. To make cruise control operate again, have to restart the car with lights in the "Off" position.

The jokes are totally warranted, but seriously, I've come to realize cruise control isn't an option for me, so any suggestions are very appreciated!

Video's & pics no problem.

Thanks and

 

[YezusLX]

Watching this because I am about two seconds from swapping clock springs due to cruise failure...

 

[KliersLC]

Interesting...

Wee usually don't get unique problems posted here that haven't been addressed multiple times over the years. A few things to check:

1. brake fluid reservoir at the appropriate level
2. normal function of the brake light on the dash--illuminates w/ application of the hand brake and low fluid state.
3. Properly installed brake light switch on the brake pedal.

All of these are unlikely culprits based on your description, but it helps to verify that everything has been checked.

By my estimation, you have three possible culprits:
1. LED lights somewhere on your vehicle (likely tail lights)
2. Incorrectly wired trailer harness.
3. Faulty trailer harness converter.

There have been folks that have had CC issues that were definitively traced back to LED lights, but none had your specific symptoms. On that note, some follow up questions:

With the headlights off, cc set, will operating the turn signal cancel the cc?
Does turning on the parking lights cancel the cc, or must it be the headlights?
When set to auto lights, and it gets dark with the cc set, will the automatic engagement of the lights cancel the cc?

I've used "cancel" but we'll also need to know if it is executing a "cancel" function or an "off" function. For example: cc set, you turn on the lights, cc disengages, you turn off the lights---if you execute the "resume" command will the cc re-engage?

I'll dig around for the instructions, but it would also be worthwhile to check if the CC ecu has any malfunction codes stored.

 

[YezusLX]

Assuming LEDs can be traced as a culprit here. Would adding a cancel resistor resolve this issue?
Faulty ABS wheel sensor perhaps loose or making poor contact?

 

[KliersLC]

Cruise Control OBD

Since no one ever seems to be able to find it: A. Turn the ignition switch on. B. Turn the control switch to SET/Coast position, and keep it there. C.Push the main switch ON. D.check that the indicator light "CRUISE" lights-up in the combination meter. E.Turn the SET/Coast switch...

forum.ih8mud.com

This was in the 80 series forum, but I believe it is valid for the 100 as well.

 

[KliersLC]

Assuming LEDs can be traced as a culprit here. Would adding a cancel resistor resolve this issue?
Faulty ABS wheel sensor perhaps loose or making poor contact?

I believe so, but I'm not sure how to figure out which value for the resistor. It could be an ABS sensor, but that wouldn't be specific to turning on the lights, so if it is repeatable and only related to turning on the lights, the fault "should" be where those two systems intersect.

 

[YezusLX]

I believe so, but I'm not sure how to figure out which value for the resistor. It could be an ABS sensor, but that wouldn't be specific to turning on the lights, so if it is repeatable and only related to turning on the lights, the fault "should" be where those two systems intersect.

I now have a starting point! Thank you. TIme to bust out the ole multimeter and get to some detective work.

 

[KliersLC]

I went rounds with an 04 Sienna with the laser cruise control that refused to function with the windshield wipers on. We finally figured out that the laser is unreliable in the rain, so toyota designed it to be disabled when the wipers were on--you had to switch to regular cruise control via manipulating the lever in a certain way. The mechanism of switching was not intuitive, and not spelled out in the van anywhere--I guess there are perks to reading the owner's manual

 

[YezusLX]

Thats interesting. I wonder if the current draw ran on the same circuit causing it to default to off due to the spike in current pull from the "laser".

 

[Bisho]

Watching this because I am about two seconds from swapping clock springs due to cruise failure...

My cruise control started shutting itself off. Ended up being bad steering rack bushings. Since I replaced the rack, all is good.

 

[YezusLX]

My cruise control started shutting itself off. Ended up being bad steering rack bushings. Since I replaced the rack, all is good.

This is interesting because I had just replaced mine. Had all the mess with Cardone "ServiceRite" rack bushings. Fixed said mess and now, no worky.

 

[jLB]

"How do I set my laser printer to stun?"

Now you’ve piqued my interest…

I don’t know how to set my laser printer to “stun” or “kill”…

Any hints?

 

[deeptide]

Interesting...

Wee usually don't get unique problems posted here that haven't been addressed multiple times over the years. A few things to check:

1. brake fluid reservoir at the appropriate level
2. normal function of the brake light on the dash--illuminates w/ application of the hand brake and low fluid state.
3. Properly installed brake light switch on the brake pedal.

All of these are unlikely culprits based on your description, but it helps to verify that everything has been checked.

By my estimation, you have three possible culprits:
1. LED lights somewhere on your vehicle (likely tail lights)
2. Incorrectly wired trailer harness.
3. Faulty trailer harness converter.

There have been folks that have had CC issues that were definitively traced back to LED lights, but none had your specific symptoms. On that note, some follow up questions:

With the headlights off, cc set, will operating the turn signal cancel the cc?
Does turning on the parking lights cancel the cc, or must it be the headlights?
When set to auto lights, and it gets dark with the cc set, will the automatic engagement of the lights cancel the cc?

I've used "cancel" but we'll also need to know if it is executing a "cancel" function or an "off" function. For example: cc set, you turn on the lights, cc disengages, you turn off the lights---if you execute the "resume" command will the cc re-engage?

I'll dig around for the instructions, but it would also be worthwhile to check if the CC ecu has any malfunction codes stored.

Hey KliersLC,

Just wanted to drop a quick note to say thanks for your help with my headlight/cruise control problem on the forum. The issue was as unique as it was mystifying, and your suggested list of probable causes was really helpful. Turns out you hit the bull's eye with the LED taillights suggestion!

It's cool how you're able to diagnose problems like this online, and it's saved me a lot of time (and likely a few bucks on mechanic fees). I appreciate your insights and the overall supportive vibe of this community.

 

[KliersLC]

Hey KliersLC,

Just wanted to drop a quick note to say thanks for your help with my headlight/cruise control problem on the forum. The issue was as unique as it was mystifying, and your suggested list of probable causes was really helpful. Turns out you hit the bull's eye with the LED taillights suggestion!

It's cool how you're able to diagnose problems like this online, and it's saved me a lot of time (and likely a few bucks on mechanic fees). I appreciate your insights and the overall supportive vibe of this community.

I'm glad I could be helpful! Also, thank you for circling back and identifying the issue!