• 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.

For symptom byte information, refer to Symptom Byte List.

The rear fascia antenna is located in the rear fascia 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 and the exterior rear closure touch pad is pressed, the keyless entry control module communicates with the rear fascia keyless entry antenna .

• The rear closure touch pad is pressed.
• The scan tool activates a device control function to simulate the above action.

The keyless entry control module detects a short to ground on the rear fascia keyless entry antenna signal circuit.

The keyless entry control module detects a short to B+ or an open on the rear fascia keyless entry antenna signal circuit.

Rear closure will not open when rear closure touch pad is pressed.

• A current DTC will clear when the conditions for setting the DTC are no longer present.
• A history DTC will clear after 40 malfunction-free ignition cycles.

Remote Function Schematics

Master Electrical Component List

Keyless Entry System Description and Operation

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Control Module References for scan tool information

1. Ignition ON.
2. Verify that DTC B3122, B3123, or B3124 is not set.
• If any of the DTCs are set

  Refer to Diagnostic Trouble Code (DTC) List - Vehicle.

• If none of the DTCs are set
3. Refer to Circuit/System Testing.

1. Ignition OFF, disconnect the harness connector at the T10 Keyless Entry Antenna, ignition ON.
2. Test for less than 1 V between the signal circuit terminal 1 and ground.
• If 1 V or greater
1. Ignition OFF, disconnect the harness connector at the K84 Keyless Entry Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K84 Keyless Entry Control Module.
• If less than 1 V

Note: When using the MIN MAX function, autorange on the DMM may not function properly. To ensure accurate test results, turn off autorange and manually set the DMM range to 000.0 V.

3. Ignition OFF, install a DMM between the signal circuit terminal 1 and ground. Set the DMM to capture DC voltage using the MIN MAX function. Turn off autorange and manually set the DMM range to 000.0 V.
4. Lock the vehicle doors using the keyless entry transmitter. Activate the antenna by pressing the rear closure touch pad.
5. Verify the MAX voltage captured by the DMM is greater than 1 V.
• If 1 V or less
1. Ignition OFF, disconnect the harness connector at the K84 Keyless Entry Control Module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Ω in the signal circuit end to end.
• If 2 Ω or greater, repair the open/high resistance in the circuit.
• If less than 2 Ω, replace the K84 Keyless Entry Control Module.
• If greater than 1 V
6. Test for less than 1 V between the low reference circuit terminal 2 and ground.
• If 1 V or greater
1. Ignition OFF, disconnect the harness connector at the K84 Keyless Entry Control Module, ignition ON.
2. Test for less than 1 V between the low reference circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K84 Keyless Entry Control Module.
• If less than 1 V

Note: When using the MIN MAX function, autorange on the DMM may not function properly. To ensure accurate test results, turn off autorange and manually set the DMM range to 000.0 V.

7. Install a DMM between the signal circuit terminal 1 and the low reference circuit terminal 2. Set the DMM to capture DC voltage using the MIN MAX function. Turn off autorange and manually set the DMM range to 000.0 V.
8. Lock the vehicle doors using the keyless entry transmitter. Activate the antenna by pressing the rear closure touch pad.
9. Verify the MAX voltage captured by the DMM is greater than 1 V.
• If 1 V or less
1. Ignition OFF, disconnect the harness connector at the K84 Keyless Entry Control Module.
2. Test for infinite resistance between the low reference circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Ω in the low reference circuit end to end.
• If 2 Ω or greater, repair the open/high resistance in the circuit.
• If less than 2 Ω, replace the K84 Keyless Entry Control Module.
• If greater than 1 V
10. Replace the T10 Keyless Entry Antenna.
11. Lock the vehicle doors using the keyless entry transmitter. Activate the antenna by pressing the rear closure touch pad.
12. Verify DTC B3121 is not set.
• If DTC B3121 is set

  Replace the K84 Keyless Entry Control Module.

• If DTC B3121 is not set
13. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

• Low Frequency Rear Bumper Antenna Replacement
• Control Module References for keyless entry control module replacement, programming, and setup