For 1990-2009 cars

### Circuit Description

The calibrations for the Remote Control Door Lock Receiver (RCDLR) are stored in EEPROM. When the ignition is first turned On, the receiver performs internal tests on the EEPROM and can determine the integrity of the EEPROM's non - volatile memory. The receiver compares its previously stored checksum with the checksum calculated when the ignition was first turned On. If the two checksums do not match, the receiver indicates that a calibration error (checksum error) has occurred.

### Conditions for Setting the DTC

• | The stored checksum does not match the calculated checksum.

• | The receiver detects an internal memory malfunction (checksum error).

• | This condition must occur when the ignition is first turned On.

### Action Taken When the DTC Sets

• | Stores a DTC B2556 in the receivers memory.

• | Disables all remote control functions.

### Conditions for Clearing the DTC

• | The conditions for the fault are no longer present.

• | The use of a scan tool.

• | A history DTC will clear after 50 consecutive ignition cycles if the condition for the fault is no longer present.

• | This DTC requires an ignition cycle in order to change from a current to history.

### Diagnostic Aids

Because the EEPROM is not removable from the receiver and a DTC B2556 is an internal malfunction to the receiver, the repair procedure is to replace the RCDLR. Program the transmitters to the new replacement receiver. Refer to Transmitter Programming.