B1658 EEPROM Checksum Error - Antitheft

Circuit Description

The PASS-Key(R) III Theft Deterrent Module performs an internal (checksum) function test on the EEPROM each time that the ignition switch is turned to the ON position. If the EEPROM fails this function test, the Pass-Key(R) III module will indicate a malfunction is current.

Conditions for Setting the DTC

The Pass-Key(R) III module detects an internal checksum test malfunction.

Action Taken When the DTC Sets

^ DTC B1658 is stored in the Pass-Key(R) III module memory.
^ No driver warning message is displayed for this DTC.

Conditions for Clearing the DTC

^ The Pass-Key(R) III module no longer detects an internal checksum malfunction.
^ A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.
^ Use a scan tool.

Diagnostic Aids

Since the EEPROM cannot be removed from the Pass-Key(R) III module and DTC B1658 is an internal Pass-Key(R) III module malfunction, the Pass-Key(R) III module may be replaced. Refer to the diagnostic table.

Test Description

The numbers below refer to the step numbers on the diagnostic table:

1. Perform the Theft Deterrent Diagnostic System Check before continuing with the diagnosis of this DTC.
2. Clear all DTCs and cycle the ignition in order to verify that the DTC did not falsely set.
4. Clear all DTCs when the repair is complete. Verify that the DTC did not reset.