Cruise Control diagnosis

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Jan 12, 2006
Threads
85
Messages
1,110
Location
Chicago!
Got an '88 4Runner 3.0 with a 5 speed and the cruise is not working "ever since" I had er apart to put on a T-belt and VCG set. It's my dad's truck and I did not confirm that the cruise worked prior to my touching it and I don't have my FSM at my fingertips to aid with diagnosis...hoping for some help here.

Here's what I know...plenty of vacuum going to the servo.

The little light on the dash-mounted cruise module/switch lights up like it should but we get no action.

I probed the wires going to the servo to check for power when the cruise is activated, there are three, white green and yellow I do believe...I only probed the green/yellow and I got a little flash of power but then nothing. And this flash was just as my "repair assistant/girlfriend" turned the cruise switch to "set." She was a little freaked out being in a car on jackstands revving the motor to any speed over 30 and hitting the switch but a darn good sport/helper!

Potential major issue, the EGR vacuum modulator melted, so I don't know if it is causing a significant enough vacuum leak to make it so the servo won't work? I did not plug the vacuum lines to it to rule it out as an issue.

I will triple check tomorrow, but the vacuum line going to the servo had no leaks, and sucks with the strength of Austin Powers' penis pump from what I saw!

I'm guess I'll know tomorrow what the tests might be as I'll be at my FSM. But any help, insight would be appreciated. I'm not sure how to test the servo but there must be a way?

And if he's right it seems very coincidental that after my work the cruise stops functioning. And I really don't think it has anything to do with the melted EGR vacuum modulator IMO.
 
Is the check engine light on? I know in later models if the check engine light is on the cruise control will not work. May be the same for the brake light.

Beyond that, there is a FSM online and linked in the FAQ thread.
 
Is the check engine light on? I know in later models if the check engine light is on the cruise control will not work. May be the same for the brake light.

Beyond that, there is a FSM online and linked in the FAQ thread.

Oh, that's nice, the FSM link.

I don't think the MIL will affect the cruise in this thing. In fact I'm almost sure it does not. Nonetheless, it's not on. But what will affect it as most of us know I'm sure, is the brake warning light. And that is not on.
 
Anyone else got anything? I don't wanna open up that FSM link at work...potential copyright issues with the ole employer!

I'm going to punt as time is not on my side and hit a U-pull it bone yard and see if I can find a servo (and EGR modulator too!) after work and go from there if nobody has anything.

EDIT****

Piece of cake with the FSM, s***, the cruise module/switch even gives flash codes! Hah!

Servo has a bad diaphragm...Self-serve bone yard was closed!

Should have it working by the weekend provided I can find a good/correct servo.
 
Last edited:
Does anyone know what years/engine's have the same cruise servo?

Will a 22RE servo work in a 3.0 truck?

I'm guessing all vacuum controlled servos are the same.
 
Back
Top Bottom