B1556 GMC – Odometer Mileage & EEPROM Disagree

B1556 GMC Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

B1556 GMC Possible Causes

Faulty Instrument Panel Cluster (IPC),Instrument Panel Cluster (IPC) harness is open or shorted,Instrument Panel Cluster (IPC) circuit poor electrical connection

B1556 GMC Description

The Instrument Panel Cluster (IPC) uses no external circuits for the operation that sets this Diagnostic Trouble Code (DTC). The IPC stores 3 redundant copies of the vehicle odometer mileage within the EEPROM. The 3 EEPROM mileage records stored mileage records must agree.