Diagnostic Instructions
DTC Descriptor
- DTC B3101
 Keyless Entry Data Link Circuit
For symptom byte information, refer to Symptom Byte List.
Diagnostic Fault Information
Circuit  | Short to Ground  | Open/High Resistance  | Short to Voltage  | Signal Performance  | 
|---|
B+  | B3101 00  | B3101 00  | —  | —  | 
Serial Data  | B3101 00  | B3101 00  | B3101 00  | B3101 00  | 
Serial Data  | B3101 00  | B3101 00  | B3101 00  | B3101 00  | 
Low Reference  | —  | B3101 00  | —  | —  | 
Circuit/System Description
The body control module communicates with the remote control door lock receiver through the keyless entry serial data circuits. When any button on the keyless entry transmitter is pressed, the transmitter sends a signal to the remote control door lock receiver. The remote control door lock receiver sends a function request to the body control module, depending on which button is pressed on the transmitter. The body control module receives
the message and performs the appropriate function.
Conditions for Running the DTC
The body control module monitors for this DTC at all times.
Conditions for Setting the DTC
No response is received from the remote control door lock receiver after the body control module requests information from or sends configuration commands to the remote control door lock receiver.
Action Taken When the DTC Sets
In the case of power loss, the remote control door lock receiver is disabled for 65 s. Otherwise no action is taken.
Conditions for Clearing the DTC
- A current DTC will clear when the fault is no longer present.
 - A history DTC will clear after 40 consecutive ignition cycles without a fault present.
 
Reference Information
Schematic ReferenceRemote Function Schematics
Component Connector End ViewsMaster Electrical Component List
Description and OperationKeyless Entry System Description and Operation
Electrical Information ReferenceScan Tool ReferenceControl Module References for scan tool information
Circuit/System Testing
- Ignition OFF and all vehicle systems OFF, scan tool disconnected, disconnect the harness connector at the K77 Remote Control Door Lock Receiver. It may take up to 2 min for all vehicle systems to power down.
 - Test for less than 30 Ω between the low reference circuit terminal 1 and ground.
 - Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
 - Test for less than 2 Ω in the low reference circuit end to end.
 - If 2 Ω or greater, repair the open/high resistance in the circuit.
 - If less than 2 Ω, replace the K9 Body Control Module.
 
- Ignition ON.
 - Test for greater than 11.5 V between the B+ circuit terminal 4 and ground.
 - Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
 - Test for infinite resistance between the B+ circuit and ground.
 - If less than infinite resistance, repair the short to ground on the circuit.
 
- Test for less than 2 Ω in the B+ circuit end to end.
 - If 2 Ω or greater, repair the open/high resistance in the circuit.
 - If less than 2 Ω, replace the K9 Body Control Module.
 
- Test for 1–6 V between the serial data circuit terminal 3 and ground.
 - Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
 - Test for infinite resistance between the serial data circuit and ground.
 - If less than infinite resistance, repair the short to ground on the circuit.
 
- Test for less than 2 Ω in the serial data circuit end to end.
 - If 2 Ω or greater, repair the open/high resistance in the circuit.
 - If less than 2 Ω, replace the K9 Body Control Module.
 
- Ignition OFF, disconnect the harness connector at the K9 Body Control Module, ignition ON.
 - Test for less than 1 V between the serial data circuit and ground.
 - If 1 V or greater, repair the short to voltage on the circuit.
 - If less than 1 V, replace the K9 Body Control Module.
 
- Ignition OFF, disconnect the X1 and X2 harness connectors at the K9 Body Control Module, ignition ON.
 - Test for less than 1 V between the K9 Body Control Module serial data circuit terminal 27 X2 and ground.
 - Ignition OFF.
 - Test for infinite resistance between the K9 Body Control Module serial data circuit terminal 27 X2 and ground.
 - Test for less than 2 Ω between the K9 Body Control Module serial data circuit terminal 27 X2 and the K77 Remote Control Door Lock Receiver serial data circuit terminal 2.
 - Replace the K77 Remote Control Door Lock Receiver.
 - Verify DTC B3101 does not set while operating the vehicle under the conditions for running the DTC.
 - All OK.
 
Repair Instructions
Perform the  Diagnostic Repair Verification after completing the repair.
Control Module References for body control module or remote control door lock receiver replacement, programming and setup.