TIGR2

I own a 2002 S2000 with 162k miles. Second owner - purchased with 22k from first owner.

I use cruise control all the time, even on residential streets. (if not, I find myself at 50 mph plus in a 35 mph zone.) When traveling in I-75, the cruise control completely stopped working. About 100 miles later, the third cylinder coil failed (probably unrelated other than on the same trip). Coil replaced and engine runs normal.

Cruise control now works if set under 52 mph. Prior to problem, if set at 50 mph, it set immediately and held 50 mph. Now, it drops to 48 mph then returns to 50 mph.

If travel is at higher speed (75 mph highway), speed slowly declines from set speed.

I have read all the cruise control posts back to 2011 without finding the cause. Some threads mentioned an adjustment to the cruise control module. Would one of you offer more help?

zeroptzero

Does the speed fluctuate up and down, if so that is pretty normal for older systems like ours, even newer cars like my daily driver will have some fluctuation. If it goes up and down but seems to center around the set speed then I'd say it is normal. If it drops and stays low then that is not normal.

There is a procedure to install and set the cruise control cable, doubt that is an issue unless the system was disassembled in the past. Also check the throttle cable for excess slack, you should have a 1/4 inch deflection max. in the throttle cable at the throttle body.

TIGR2

Speed does NOT fluctuate up and down. Set at 50, drops to 48 then returns and holds at 50 mph.

Set at 70 mph, speed just slowly drops. Takes about one minute to fall from 70 to 60 before I press the gas (I do not want to get run over going that slow).

Billman250

Does the speedo itself ever lag behind, or is it always consistent? Take the cruise control out of the equation for a moment.

TIGR2

Never noted any issue with speedo accuracy. Seems to react to throttle as expected.

Micalbertl

I don't really have any help to offer nor have I experienced this, but I also use cruise control a lot so bump.

windhund116

From Service Manual I get:

1.) Check Variable Speed Signal circuit (VSS). PG 22-94 (2000-2008, Service Manual).

2.) Check Cruise Control actuator. PG 4-68.

TIGR2

Thank you for your input.
Over the 14 years I have owned the 2002 S2000, I never needed the manual, as most repairs are done by a professional mechanic. Following a search of this site, I decided to purchase one. I found ManualsInc.com and paid $4.99 for the download. I would have bought one years ago at that price. When I looked in 2004, cost was $75.