B1556 PZM EEPROM Write Error

Circuit Description:
The test for DTC B1556 is run for each write or Block of writes to the EEPROM. The PZM writes to an EEPROM cell and then reads the data hack.

DTC Will Set When:
The data read by the PZM does not match the data written to EEPROM after two consecutive attempts.

DTC Will Clear When:
The data read by the PZM matches the data written to the EEPROM.

Troubleshooting Hints:
If DTC B1556 is set, Clear DTCs and Cycle the ignition. If DTC B1556 is still current, replace PZM.