Cruise Control - Inoperative/Malfunctioning

Diagnostic Chart (Part 1 Of 4):

Diagnostic Chart (Part 2 Of 4):

Diagnostic Chart (Part 3 Of 4):

Diagnostic Chart (Part 4 Of 4):

DIAGNOSTIC AIDS
In order to avoid misdiagnosis, perform the following inspections:
^ Inspect for proper operation of the brake lamps.
^ Visually inspect all fuses relative to the cruise control system.
^ Inspect all connectors for poor terminal retention, corrosion, or damage.
^ Inspect the throttle linkage/cable for mechanical binding.
^ Inspect the cruise control cable adjustment
^ EMI on the speed sensor signal circuit may cause erratic operation.

PCM Inhibit
The PCM will inhibit (not allow) cruise control if one or more of the following conditions has occurred:
^ When park, reverse, neutral, or first gear is indicated by the park/neutral switch
^ When certain Diagnostic Trouble Codes (DTC) are stored. Refer to the appropriate DTC(s) in the Service Manual.
^ When an over/undercharged battery condition exists
^ With low engine RPM
^ With high engine RPM (Fuel Cut-off)

THE CRUISE CONTROL TESTER
When this tester is used on some vehicles with high resistance or an open in the cruise control module ground circuit, the tester's LED(s) will light abnormally. For example, the brake/clutch and VSS LED(s) will light normally, but the ignition LED will be dim with the ON/OFF switch in the OFF position. However, with the ON/OFF switch in the ON position, only the VSS LED will light. If you come upon the above situation, inspect the ground circuit before continuing with