With the ignition switch in RUN, battery positive voltage (B+)
is applied on CKT 1141 (BRN) to terminal F of the cruise control
module. Moving the CRUISE switch to the ON position applies battery positive
voltage (B+) on CKT 397 (GRY) to terminal A of the
cruise control module. If the brake pedal is released, battery positive
voltage (B+) is applied on CKT 420 (PPL) at the cruise control module
terminal D. If the brake pedal is pressed, battery positive voltage
(B+) is present on CKT 20 (LT BLU) (Pontiac) or CKT 17 (WHT)
(Buick/Oldsmobile) at the cruise control module terminal G.
When the CRUISE switch is moved to the R/A position, battery positive
voltage (B+) is applied on CKT 87 (GRY/BLK) to terminal C of
the cruise control module. When the SET button is pressed, battery positive
voltage (B+) is applied on CKT 84 (DK BLU) at terminal B
of the cruise control module. The PCM supplies the vehicle speed signal
on CKT 817 (DK GRN/WHT) to terminal K of the cruise control
module. In operation, the vehicle speed signal voltage oscillates between
a high of battery positive voltage (B+) and a low of 0.5 V. The
cruise control module ground is connected on CKT 1150 (BLK) to ground.
The cruise control engaged output signal is supplied to the PCM on CKT 85
(WHT) at terminal J of the cruise control module. The cruise inhibit
signal from the PCM on CKT 83 (DK GRN) to terminal H of
the cruise control module.
The PCM has the ability to disable cruise control if conditions
are detected which would make cruise control operation undesirable. The PCM
inhibits cruise control operation under any of the following cruise control
inhibit conditions:
| • | The transaxle is in PARK, NEUTRAL, LOW or REVERSE. |
| • | Engine speed is too high. |
| • | Vehicle speed is too high. |
| • | Vehicle acceleration or deceleration rate is too high. |
| • | Antilock brake system/traction control system is active for more
than two seconds. |
If the PCM determines that any of the cruise control inhibit conditions
are present, the PCM requests that the cruise control module disengage cruise
control. The PCM accomplishes this request by grounding CKT 83 (DK GRN).
If the cruise status signal, sent by the cruise control module to the PCM
on CKT 85 (WHT), indicates that the cruise control is still engaged after
the PCM has requested that cruise control disengage, the PCM sets a DTC.
