Is the cruise control not working in your NC? Here's what you should check:
0.
- Do you have the cruise control wiring installed? Check the brake switch: if it has 4 wires going to it, you're good.
- Does your ECU support cruise control? The L831 ECUs used in pre-facelift 1.8 NC1 engines do NOT support cruise control without modification.
- Do you have the correct brake switch?
The correct one has a 4-pin inside connector, not 2.
An example of a proper switch: Facet 7.1272
- Is the brake switch properly adjusted? This is a common issue.
IMPORTANT: First install the switch, then plug in the connector. This sets the switch correctly.
If you do it the other way around, the switch will be misadjusted. In that case, you'll need to reset and reinstall it as described below.
To reset the switch: pull out the plastic lock tab inside the switch socket until it clicks.
switch locked. Pull out white locker

The switch plunger will start moving freely — this indicates it's ready for adjustment.
switch unlocked - ready to adjust

A properly installed and adjusted switch does not require re-adjustment. You can unplug and replug it without issues.
- Measure the voltage on the brake switch (with ignition on — easiest if the switch is removed)
wyłącznik ma 2 sekcje, gdy jedna jest zwarta druga jest rozwarta - i vice versa.
expected values
Section 1: 0V when switch is released, 12V when pressed

Section 2: 12V when released, 0V when pressed

Measure resistance between the following two pins of the cruise control panel GROUND-CRUISE (with the panel disconnected from the car):

expected values
- No button pressed: open circuit
- on/off: 0 ohm
- cancel 120 ohm
- -/set 680 ohm
- +/res 2200ohm





Measure voltage between the following pins of the cruise control clockspring GROUND-CRUISE (everything connected, ignition on):
- No button pressed: 5V
- on/off: 0 V
- cancel approx 1.1V
- -/set approx 3.2V
- +/res approx 4.2V
podłączenie multimetru stanowi pewną trudność, ale jest wykonalne - bądźcie cierpliwi 🙂


if you get constant 0V here
- there is issue with CC harness
- ECU does not support Cruise Control (L831xx for NC1 1.8L does NOT)
if you get constantly 5V there regardless of buttons pressed, and buttons were checked at point 4 and give correct resistance measurements: possible clockspring fault