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Removal & Installation

Some PCM's use a CALPAC as well as a PROM. See Fig 1 . The CALPAC must also be removed from old PCM and installed in new one. Removal and replacement procedures for CALPAC are same as for PROM. See PROGRAMMABLE READ-ONLY MEMORY (PROM) . If units are installed improperly, grounding diagnostic test lead will set Code 52.

Fig 1: Locating PROM & CALPAC On PCM

Courtesy of GENERAL MOTORS CORP.