Diagnostic Aids

Check for poor connection at the BCM. Inspect harness connectors for backed out terminals, improper terminal mating, broken connector locks, improperly formed or damaged terminals and poor terminal-to-wire connection (terminal crimped over wire insulation and not conductors).
Inspect wiring harness for damage. Check for broken or chaffed insulation.
If fault is suspected to be intermittent, wiggling harness wiring may help in locating fault.

Fig 1: Security System Controller In Learn Mode Testing Flow Chart (1 Of 2)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Security System Controller In Learn Mode Testing Flow Chart (2 Of 2)

Courtesy of GENERAL MOTORS CORP.