Circuit Description
The remote control door lock receiver (RCDLR) communicates with the body control module (BCM) through the keyless entry serial data circuit. When any button on the keyless entry transmitter is pressed, the transmitter sends a signal to the RCDLR. The RCDLR sends a lock, unlock, rear release, or panic alarm request to the BCM, depending on which button is pressed on the transmitter. The BCM receives the message and performs the appropriate function. The BCM also uses the keyless entry serial data circuit in order to communicate with the RCDLR when programming transmitters.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B3103 Short to Voltage in Serial Data Circuit
Conditions for Running the DTC
| • | The system voltage is at least 9 volts and no more than 16 volts. |
| • | The BCM must be receiving a message from the RCDLR while in the program mode. |
Conditions for Setting the DTC
The BCM detects a short to voltage in the keyless entry serial data circuit.
Action Taken When the DTC Sets
The keyless entry system will not operate.
Conditions for Clearing the DTC
| • | A current DTC will clear when the fault is no longer present and the ignition switch is cycled. |
| • | A history DTC will clear after 100 consecutive ignition cycles without a fault present. |
| • | A scan tool may be used to clear history and current DTCs. |
Diagnostic Aids
| • | Always begin diagnosis with the first DTC listed on the scan tool. |
| • | Perform a visual inspection for loose or poor connections at all related components. |
| • | If DTC B3103 is a history DTC, the fault may be intermittent. Refer to Testing for Electrical Intermittents in Wiring Systems. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
The B+ voltage should be present on the serial data terminal when tested with a DMM, but should not illuminate the test lamp. An illuminated test lamp indicates a short to voltage in the serial data circuit.
-
This step checks for a short to voltage in the keyless entry serial data circuit.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Keyless Entry Schematics | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Is the DTC B3103 a current code? | Go to Step 3 | Go to Diagnostic Aids |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 5 | |
Test the keyless entry serial data circuit for a short to voltage. Refer to Testing for a Short to Voltage and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 6 | |
5 | Inspect for poor connections at the harness connector of the RCDLR. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
6 | Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 8 |
7 |
Important: Perform the keyless entry transmitter programming procedure when replacing the RCDLR. Replace the RCDLR. Refer to Remote Control Door Lock Receiver Replacement . Did you complete the replacement? | Go to Step 9 | -- |
8 |
Important: Perform the BCM programming procedure when replacing the BCM. Body Control Module (BCM) Programming/RPO Configuration . Replace the BCM. Refer to Body Control Module Replacement in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 9 | -- |
9 |
Does the DTC reset? | Go to Step 2 | System OK |
