Entertainment System Diagnosis

DTC B1658 EEPROM Checksum Error:

CIRCUIT DESCRIPTION
The radio (IRC) calibrations are stored in the EEPROM. When the ignition is first turned ON, the radio performs internal tests on the EEPROM to determine the integrity of its non-volatile memory. The radio compares its previously stored checksum with the checksum calculated when the ignition is first turned to ON.

CONDITIONS FOR SETTING DTC
^ The stored checksum does not match the calculated checksum.
^ The condition must occur when the ignition is first turned to ON.

ACTION TAKEN WHEN THE DTC SETS
^ The radio stores a DTC B1658 in its memory.
^ No driver warning message is displayed for this DTC.
^ The radio uses default values for any memory address in the EEPROM that is corrupt.

CONDITIONS FOR CLEARING DTC
^ This DIC requires an ignition cycle in order to change from current to history.
^ The radio no longer detects an internal memory malfunction (checksum error).
^ A history DTC clears after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.

DIAGNOSTIC AIDS
Since the EEPROM cannot be removed from the radio, DTC B1658 is an internal radio malfunction, the radio may need to be replaced.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table:
1. Perform the Radio/Audio System Diagnostic System Check before continuing with the diagnosis of this DTC.
2. Clear all DTCs and cycle ignition to check that the DTC did not falsely set.
4. Clear all DTCs after the repair procedure is complete.