Removal & Installation
Some ECM models use a CALPAC as well as a PROM. See Fig 1 . If replacing ECM, remove CALPAC from old ECM and install in new ECM. Removal and replacement procedures for CALPAC are same as for PROM. See PROGRAMMABLE READ-ONLY MEMORY (PROM) under IGNITION SYSTEM. If units are improperly installed, grounding diagnostic test lead will set Code 52.