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