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Home >> GMC >> 1994 >> Forward Control 7.4 N >> Repair and Diagnosis >> Engine Performance >> Remove, Overhaul & Install >> Engine Controls - Remove/Install/Overhaul >> Powertrain Control Module (Pcm) >> Calpac >> Removal & Installation
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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
G90G15723Courtesy of GENERAL MOTORS CORP.