Powertrain Controls - ECM/PCM

PROM ERROR (faulty or incorrect PROM)
Check that all pins are fully inserted in the socket. if OK, replace prom, clear memory and recheck. If DTC 51 reappears, replace PCM.
If PCM is faulty and must be replaced, "TDC OFFSET" must be programmed into the new PCM.
When all diagnosis and repairs are completed, clear DTC(s) and verify proper operation.