For 1990-2009 cars

### 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 B3120 02: Keyless Entry Antenna 2 Short to Ground
DTC B3120 05: Keyless Entry Antenna 2 High Voltage/Open

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Right Front Door --Keyless Entry Antenna Signal | B3120 02 | B3120 05 | B3120 05 | --
Right Front Door --Keyless Entry Antenna Low Reference | -- | B3120 005 | -- | --

### Circuit/System Description

The right front door handle antenna is located in the right front door handle assembly and is used to establish low frequency communications with the keyless entry transmitter. As a vehicle with locked doors is approached with a keyless entry transmitter, known as an user identification device, and the exterior door handle is activated, the keyless entry antenna broadcasts a challenge to the transmitter in an approximately 1 meter range. If the response from the transmitter via radio frequency is valid, the locked door will be passively unlocked/unlatched and allow the door to be opened.

### Conditions for Running the DTC

The right front door handle is lifted

### Conditions for Setting the DTC

#### B3120 02

The keyless entry control module detects a short to ground on the right front door keyless entry antenna circuit.

#### B3120 05

The keyless entry control module detects a short to B+ or an open on the right front door keyless entry antenna 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

Remote Function Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Keyless Entry System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the T10D right front door handle antenna.
2. Ignition ON, verify a test lamp does not illuminate between the signal circuit terminal A and ground.

⇒ | If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the keyless entry control module.

3. Connect a DMM, set to capture AC voltage using the MIN MAX function, between the signal circuit terminal A and the low reference circuit terminal B.
4. Pull the right front door handle. Verify the DMM captured an AC voltage signal.

⇒ | 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 keyless entry control module.

5. If all circuits test normal, test or replace the T10D right front door handle assembly.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Front Side Door Outside Handle Replacement

• | Control Module References for keyless entry control module replacement, setup, and programming