B2560 RKE Message Validation Error (1ST Design)

Diagnostic Trouble Code (DTC) Chart:

CIRCUIT DESCRIPTION
The Remote Control Door Lock Receiver (RCDLR) monitors serial communications between it and the Body Control Module (BCM) over the Class 2 data bus. Each valid message received by the RCDLR contains a changing unique rolling code.

CONDITIONS FOR SETTING THE DTC
The fault is set after the RCDLR receives 16 consecutive incorrect messages.

ACTIONS TAKEN WHEN THE DTC SETS
Stores a DTC B2560 in the receivers memory.

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 are no longer present.

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.
^ Any condition which results in the interruption of power to the receiver.
^ Out of range battery or ignition voltage. Normal voltage range is 9.0-16.0 V.
^ A loose or damaged ground.
^ A loose or damaged power supply.

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.