Cruise control – circuit operation

CRUISE CONTROL – CIRCUIT OPERATION

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    The Cruise Control System can be disabled in one of four ways: 6.   $' % ! &$! ) &   % "'& &   "!% & !  $ !(  "!)$ $! &  $' % ! + &$!     ('' "' "   $%  &  %& %"  !$* 7. The RES/DECEL Switch is depressed, signalling the Cruise Control ECU (Z121) to disengage the system. 8. The brake pedal is depressed and a vacuum valve in the Brake Switch Vent Valve opens (X112). This vents vacuum to the actuator valve and releases the throttle. 9. The Voltage applied to Cruise Control ECU (Z121) terminal 9 is interrupted, causing the Cruise Control ECU (Z121) to turn off the vacuum pump and de-energise the vacuum solenoid valve. This voltage path is interrupted when the brake pedal is depressed, the Clutch Pedal is depressed, or the vehicle is in Park or Neutral. With the brake pedal depressed, the Brake Switch Vent Valve (X112) moves to 1 and the circuit is interrupted. With the vehicle in Park or Neutral, the Park/Neutral Position Switch (X167) energises the Cruise Control Lockout Relay (K110) by grounding the relay’s coil. The relay then opens its contacts, interrupting the circuit. With the clutch pedal depressed, the Clutch Switch (X200) moves to 1 and the circuit is interrupted. NOTE: For 300 Tdi vehicles equipped with an EDC Diesel engine, the Cruise Control System can also be disabled by the Engine Control Module (ECM) (Z132) when an engine fault has been detected.