Cruise Control - (W/Electro Stepper Mtr.) Diagnostics
File In Section: 9 AccessoriesBulletin No.: 83-90-08
Date: June, 1998
INFORMATION
Subject:
New Tool J 42958, Revised Charts and Schematics for Cruise Control Diagnosis
Models:
1988-98 Passenger Cars and Trucks with Electro-Motor (Stepper Motor) Cruise Control Systems
A new Cruise Control Tester, J 42958, has been sent to all dealers as part of the 1998 Essential Tool Package. This tool will work on all Stepper Motor Cruise Control systems for past model years.
The charts and schematics in this bulletin can be used in place of the diagnostic charts in previous Service Manuals when this new tool is used. These charts will be included in the 1999 Service Manuals.
Cruise Control Inoperative
Important
To avoid misdiagnosis:
^ Check for proper operation of brake lamps.
^ Check throttle linkage for mechanical binding which could cause the system to malfunction
^ Check for stored Diagnostic Trouble Codes (DTCs) in the PCM. Refer to Powertrain OBD System Check in Engine Controls.
The PCM will inhibit cruise control:
^ When vehicle speed is less than 40 km/h (25 mph).
^ When PARK, REVERSE, NEUTRAL, or 1st gear is indicated by the Park/Neutral Position Switch,
^ When an over/undercharged battery condition exists.
^ With low engine RPM.
^ With high engine RPM (fuel cut-off). Refer to Powertrain Control Module Description in Engine Controls for additional information.