Doors Lock Automatically, But Left Door Does Not Unlock When Actuating Left Door Lock Remote Handle

Place selector in "PARK" and lock all doors. Connect test light between ground and module "H" terminal. If left door does not unlock, proceed to step 2) . If left door unlocks, check remote handle switch ground, remote handle switch for defects, or for open in wire between remote handle switch and module (Lt. Green-Black wire).

Fig 1: Buick Automatic Door Lock Wiring Diagram

Courtesy of GENERAL MOTORS COMPANY

Fig 2: Cadillac Automatic Door Lock Wiring Diagram

Courtesy of GENERAL MOTORS COMPANY

If door did not unlock, turn ignition to "ON". Connect test light between ground and module "F" terminal. If door unlocks, replace module printed circuit. If door does not unlock, perform Left Door Unlocking Relay Test.