Code 51 - Prom

Code 51 sets if any of the following occur:

• Faulty PROM unit.
• PROM unit improperly installed (may not set a code if installed backward).
• Some PROM pins not making contact (i.e. bent).

Ensure PROM pins are not bent and are inserted properly into ECM. Ensure PROM is installed in proper direction as shown in chart.

Fig 1: Code 51 - PROM Replacement