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