B3121

DTC B3121

Circuit Description

The keyless entry antenna - rear compartment is located in the lower rear compartment area near the latch and is used as a short range low frequency (LF) transmitter. As a vehicle with a closed rear compartment lid is approached with a key fob and the exterior deck lid handle switch is pressed, the keyless entry antenna transmitter broadcasts a challenge to the key fob in an approximate 1 meter range. If the response from the key fob via radio frequency (RF) is valid, the latched rear compartment will be passively unlocked/unlatched, allowing the rear compartment area to be opened.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B3121 Keyless Entry Antenna 3 Performance

Conditions for Setting the DTC

The remote control door lock receiver (RCDLR) will set this DTC during antenna activation if the keyless entry antenna - rear compartment is open, shorted to battery or shorted to ground and an authentication occurs. The RCDLR can only set a DTC when it is the vehicle system voltage is between 9-16 volts.

Action Taken When the DTC Sets

The RCDLR will set and store a DTC B3121.

Conditions for Clearing the DTC

* The RCDLR no longer detects a open, short to power or short to ground on the antenna circuit.
* The use of a scan tool.

Test Description

Step 1 - Step 9:

Step 10 - Step 11:

The numbers below refer to the step numbers on the diagnostic table.
2. Verifies that DTC B3121 is a current DTC.
3. Testing for power and ground to the keyless entry antenna.