Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC B3121 00: Keyless Entry Antenna 3 Performance - Rear Compartment AntennaDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Keyless Entry Antenna Signal - LF Door | B3119 00 | B3119 00 | B3119 00 | -- |
Keyless Entry Antenna Low Reference - LF Door | -- | B3119 005 | -- | -- |
Keyless Entry Antenna Signal - RF Door | B3120 00 | B3120 00 | B3120 00 | -- |
Keyless Entry Antenna Low Reference - RF Door | -- | B3120 005 | -- | -- |
Keyless Entry Antenna Signal - Rear Compartment | B3121 00 | B3121 00 | B3121 005 | -- |
Keyless Entry Antenna Low Reference - Rear Compartment | -- | B3121 00 | -- | -- |
Keyless Entry Antenna Signal - Console Passive | B3123 00 | B3123 00 | B3123 00 | -- |
Keyless Entry Antenna Low Reference - Console Passive | -- | B3123 00 | -- | -- |
Keyless Entry Antenna Ignition - Console Active | B3122 00 | B3122 00 | B3122 00 | -- |
Keyless Entry Antenna Data Signal - Console Active | B3122 00 | B3122 00 | B3122 00 | -- |
Keyless Entry Antenna Clock Signal - Console Active | B3122 00 | B3122 00 | B3122 00 | -- |
Keyless Entry Antenna Low Reference - Console Active | -- | B3122 00 | -- | -- |
Circuit/System Description
The rear compartment keyless entry antenna is used to establish low frequency (LF) communications with the keyless entry transmitter. As a vehicle with a closed rear compartment lid is approached with a keyless entry transmitter, known as an electronic key, and the rear compartment lid release switch is pressed, the keyless entry antenna transmitter broadcasts a challenge to the transmitter in an approximate 1 meter range. If the response from the transmitter via radio frequency (RF) is valid, the latched rear compartment will be passively unlocked/unlatched, allowing the rear compartment area to be opened.
Conditions for Running the DTC
The rear compartment lid release switch is pressed
Conditions for Setting the DTC
An improper current level is seen on the keyless entry antenna - signal 3 circuit
Action Taken When the DTC Sets
No action is taken
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
Connector End View Reference
Description and Operation
Keyless Entry System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the rear compartment keyless entry antenna.
- Ignition ON, verify a test lamp does not illuminate between the signal circuit terminal A and ground.
- Install a DMM between the signal circuit terminal A and the low reference circuit terminal B. Set the DMM to capture AC voltage using the MIN MAX function.
- Press the rear compartment lid release switch. Verify the DMM captured an AC voltage signal.
- If all circuits test normal, test or replace the rear compartment keyless entry antenna.
| ⇒ | If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RCDLR. |
| ⇒ | If an AC voltage was not captured, test the signal circuit and the low reference circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the RCDLR. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for RCDLR replacement, setup, and programming
