B3122

DTC B3122

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptors
DTC B3122 04
- Keyless Entry Antenna 4 Performance Open Circuit

DTC B3122 3B
- Keyless Entry Antenna 4 Performance Internal Self Test Failed




Diagnostic Fault Information






Circuit/System Description

The console active antenna is located in the center console and is used as a short range low frequency (LF) antenna. The keyless entry console active antenna is only used when a keyless entry transmitter battery is low or there is a interruption with the frequency transmission of the passive antennas located in the console and headliner. When a valid transmitter is placed into the fob pocket, the brake pedal is depressed, and the ignition button is pressed, the console active antenna broadcasts a challenge to the transmitter. This causes a low frequency coupling to occur between the transmitter and the console active antenna. If the response from the transmitter is a valid response, and all of the security requirements are met, the vehicle's engine will start, or be allowed to go into accessory mode.


Conditions for Running the DTC

A transmitter validation from the console active antenna is requested.


Conditions for Setting the DTC

An improper voltage level is seen at the console active antenna.


Action Taken When the DTC Sets

The console active antenna is ignored.


Conditions for Clearing the DTC

* A current DTC will clear when the conditions for setting the DTC are no longer present.
* A history DTC will clear after 50 malfunction free ignition cycles.



Reference Information
Schematic Reference

Remote Function Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Keyless Entry System Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the console active antenna.
2. Ignition OFF, test for less than 20 ohms of resistance between the low reference circuit terminal 5 and ground.

• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the RCDLR.

3. Ignition ON, test for B+ between the supply voltage circuit terminal 2 and ground while commanding the scan tool Active Antenna output control ON.

• If not the specified value, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the RCDLR.

4. Ignition OFF, disconnect the X2 harness connector at the RCDLR.
5. Ignition ON, verify a test lamp does not illuminate between the following circuits and ground:

* Signal circuit terminal B
* Signal circuit terminal C


• If the test lamp illuminates, test the appropriate signal circuit for a short to voltage.

6. Ignition OFF, test for infinite resistance between the following circuits and ground:

* Signal circuit terminal B
* Signal circuit terminal C


• If less than the specified value, test the appropriate signal circuit for a short to ground.

7. Test for less than 2 ohms of resistance between the following signal circuits:

* Terminal B at the RCDLR and terminal 3 at the console active antenna
* Terminal C at the RCDLR and terminal 4 at the console active antenna


• If greater than the specified range, test the appropriate signal circuit for an open/high resistance.

8. If all circuits test normal, test or replace the console active antenna.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Ignition Lock Key Transmitter Antenna Replacement - Floor Console (Rear) (Ignition Lock Key Transmitter Antenna Replacement - Floor Console (Rear))Ignition Lock Key Transmitter Antenna Replacement - Floor Console (Cup Holder) (Ignition Lock Key Transmitter Antenna Replacement - Floor Console (Cup Holder))
* Control Module References (Programming and Relearning) for RCDLR replacement, setup, and programming