Cruise Control - Troubleshooting
Group 65Radios and Accessories
Bulletin Number
65 04 90 (3121)
Woodcliff Lake, NJ
October 1990
Service Engineering
SUBJECT:
Cruise Control Electrical Troubleshooting
MODELS:
All (equipped with Cruise Control with Electrical Actuator)
Situation:
Cruise Control with electric actuator (introduced in 1982) can be diagnosed by a pin by pin examination of the circuits involved (see appropriate Repair Manual and Electrical Troubleshooting Manual).
Troubleshooting procedures may contain the following information:
1) The technician is directed to use Pin 3 as a ground for voltage or resistance tests, using the 26-pin adaptor; and, 2) Pin 3 of the control unit is referred to as a "Cruise Enable" input.
Both of these items may be misinterpreted, resulting in a faulty diagnosis.
Correction:
When troubleshooting this cruise control system, consider the following points:
1) Pin 3 may not be grounded through the instrument cluster. On later vehicles, the wire attached to Pin 3 is not connected to anything else. Pin 23 should be used as a ground in all testing.
2) Pin 3 should be considered as a "cruise disable" input. Cruise control operation is not enabled by Pin 3 being grounded. Rather, cruise control operation is disabled by the application of voltage to Pin 3 (via Park/Neutral circuit).
Refer to the appropriate ETM and Repair Manual in all cases.
Warranty Status: Information only.