DTC 52

Code 52 - PROM Error (Faulty Or Incorrect CAL-PAK):

CAUTION: To prevent possible electrostatic discharge damage to the CALPAK, do not touch the component leads or remove CALPAK from carrier.

CHECK CALPAK

1. Check that all CALPAK pins are fully inserted in socket.
2. If okay, replace CALPAK, clear codes and recheck.
3. If code 52 reappears, replace ECM.
4. Clear codes, confirm "Closed Loop" operation and no "Check Engine" light.