Neon L4-2.0L VIN C (1998)
Cruise Control Switch: Description and Operation
SYSTEM OPERATION
There are two separate switch pods that operate the speed control system. The steering-wheel-mounted switches use multiplexed circuits to
provide inputs to the PCM for ON, OFF, RESUME, ACCELERATE, SET, DECEL and CANCEL modes.
When speed control is selected by depressing the ON switch, the PCM allows a set speed to be stored in RAM for speed control. To store a set
speed, depress the SET switch while the vehicle is moving at a speed between 30 and 85 m.p.h.. In order for the speed control to engage, the
brakes cannot be applied, nor can the gear selector be indicating the transmission is in Park or Neutral.
The speed control can be disengaged manually by:
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Stepping on the brake pedal
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Depressing the OFF switch
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Depressing the CANCEL switch.
NOTE: Depressing the OFF switch or turning off the ignition switch will erase the set speed stored in the PCM.
For added safety,the speed control system is programmed to disengaged for any of the following conditions:
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An indication of Park or Neutral
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An rpm increase without a VSS signal increase (indicates that the clutch has been disengaged)
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Excessive engine rpm (indicates that the transmission may be in a low gear)
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The VSS signal increases at a rate of 10 m.p.h. per Second (indicates that the co-efficient of friction between the road surface and tires is
extremely low)
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The VSS signal decreases at a rate of 10 m.p.h. per Second (indicates that the vehicle may have decelerated at an extremely high rate)
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If the actual speed is not within 20 m.p.h. of the set speed
The previous disengagement conditions are programmed for added safety.
Once the speed control has been disengaged, depressing the ACCEL switch when speed is greater than 25 m.p.h. restores the vehicle to the target
speed that was stored in the PCM.
NOTE: Depressing the OFF switch will erase the set speed stored in the PCM's RAM.
While the speed control is engaged, the driver can increase the vehicle speed by depressing the ACCEL switch. The new target speed is stored in
the PCM when the ACCEL is released. The PCM also has a "tap-up" feature in which vehicle speed increases at a rate of approx 2 m.p.h. for
each momentary switch activation of the ACCEL switch. The PCM also provides a means to decelerate without disengaging speed control. To
decelerate from an existing recorded target speed, depress and hold the COAST switch until the desired speed is reached, then release the switch.
The individual switches cannot be repaired. If one switch fails, the entire switch module must be replaced.