Cruise control switch function - GF07.13-P-3124-01H
Engaging the CC [TPM] switch (S40) always engages two of its switching contacts simultaneously. The actual input is achieved by the closing of one switching contact (e.g. for recording the vehicle speed in memory).
However, the safety contact must close simultaneously for the engine control module to recognize the input as a desired action by the driver. This serves to prevent any inadvertent engagement of the cruise control system due to a technical fault (such as a defect in the wiring harness).