Troubleshooting Hints

1. CHECK condition of BRAKE Fuse 18, STOP Fuse 1, and CRUISE Fuse 6 (Gasoline Engines) or BRAKE Fuse 18, STOP Fuse 1, CRUISE Fuse 6, and ECM-B Mini-Fuse (Diesel Engine). If any fuse is open LOCATE and REPAIR cause of overload and REPLACE Fuse.
2. CHECK that Ground G103 (Gasoline Engines) or Grounds G101 and G103 (Diesel Engine) are clean and tight.
3. CHECK that no Diagnostic Trouble Codes (DTC) which would impact operation of Cruise Control are set.
4. If the Cruise Control is reported as inoperative, check the Brake to Cruise interlock logic is functioning properly. This interlock requires that the Cruise Control Module (Gasoline Engines) or Powertrain Control Module (Diesel Engines) receive a brake-on input following the placement of the Ignition Switch in RUN before enabling Cruise Control operations.
5. Loose, binding, or poorly adjusted Cruise Control linkage for Gasoline Engines may induce erratic operation. Check that throttle linkage is properly installed and adjusted.
6. If the Cruise Control is engaged and the vehicle continually accelerates, LOCATE and REPAIR short to voltage on GRY/BLK (87) wire between Cruise Control Switch and Cruise Control Module (Gasoline Engines) or Powertrain Control Module (PCM, Diesel Engine). This condition will generate DTC 76 for vehicles with Diesel Engines.
7. If either the SET CRUISE (Coast) push-button or the R/A switch contact are held in place for over 25.5 seconds, the Cruse Control system will cease operating. The engine must be turned off to reset this interlock.
8. See the Driveability and Emissions section for the appropriate gasoline engine to address any diagnostics related to opens or shorts on the VCM Signal LT BLU/BLK (396) wire.
9. If the SET CRUISE push-button works with the OFF-ON-R/A Switch in the OFF position, then check for a short to voltage on the GRY (397) wire between the Cruise Control Switch and the Cruise Control Module (Gasoline Engine) or the Powertrain Control Module (Diesel Engine).
^ CHECK for a broken or partially broken wire inside the insulation which could cause system malfunction but prove GOOD in a Continuity/Voltage check with a system disconnected. These Circuits may be intermittent or resistive when loaded and should be checked by monitoring for a Voltage drop with the system operational (under load).
^ CHECK for proper installation of aftermarket electronic equipment which may affect the integrity of other systems.