For 1990-2009 cars only
Circuit Description
The radio (IRC) calibrations are stored in the electronically erasable programmable read only memory (EEPROM).
The radio (IRC) performs internal tests on the EEPROM. The radio attempts writing to the EEPROM and then reads the data back. This test determines the integrity of the non-volatile memory.
Conditions for Setting the DTC
When the ignition is ON, the radio (IRC) performs internal tests on the EEPROM. The tests determine the integrity of the non-volatile memory. When the data read by the radio does not match the data written to the EEPROM after 2 consecutive attempts, the radio sets DTC B1656 as current.
Action Taken When the DTC Sets
| • | DTC B1656 is stored in the module. |
| • | This DTC does not cause the display of the driver warning message. |
Conditions for Clearing the DTC
| • | The data read by the radio (IRC) matches the data written to the EEPROM. |
| • | A history DTC clears after 50 consecutive ignition cycles if the condition for the malfunction is no longer present. |
Diagnostic Aids
If DTC B1656 is set, clear the DTCs and cycle the ignition. If DTC B1656 is still current, replace the radio (IRC).
