B2560 RKE Message Validation Error (2ND Design)

Diagnostic Trouble Code (DTC) Chart:

CIRCUIT DESCRIPTION
The Remote Control Door Lock Receiver (RCDLR) for the 2nd design RKE system is integrated with the Body Control Module (BCM). A different signal from the transmitter is sent to the receiver when any of the four buttons are pressed on the transmitter. Each signal contains a message to execute a command (e.g., LOCK/UNLOCK drivers door). The receiver transforms the commands and transmits the message to the BCM, which will execute the requested command.

CONDITIONS FOR SETTING THE DTC
A message is received with the correct transmitter ID but the accompanying security information cannot be validated. A message validation counter is increased each time the receiver receives consecutive incorrect security information. When the counter reaches 16, a DTC B2560 is set.

ACTIONS TAKEN WHEN THE DTC SETS
^ Stores a DTC B2560 in the receivers memory.
^ The message validation counter is reset.
^ Receiver operation is disabled for a minimum of 20 seconds.

CONDITIONS FOR CLEARING THE DTC
^ The current status of the DTC becomes a history status when a valid message is subsequently received.
^ The use of a scan tool.

DIAGNOSTIC AIDS
The following conditions may cause intermittent transmitter or receiver operation.
^ Inspect that the transmitter battery terminals are clean and are making good contact with the battery.
^ Out of range battery or ignition voltage. Normal voltage range is 9.0-16.0 V.

TEST DESCRIPTION
The number(s) below refer to the step number(s) on the diagnostic table.
3. A weak battery may cause the transmitter to malfunction. This test determines if the battery is the cause. After replacement and programming, the transmitter is operated through all positions. A check is made to see if the DTC resets.
5. If the DTC resets the most likely cause is the transmitter.
6. Both transmitters might be out of sync. This test reprograms and synchronizes both transmitters. After reprogramming both transmitters are checked again.
7. If the DTC resets after both transmitters were reprogrammed and synchronized, the most likely cause is the receiver in the BCM.