The back up keyless entry antenna is located in the glove compartment area and is used as a short range low frequency (LF) transmitter. When a valid key fob is within the passenger compartment and the brake pedal is depressed and the ignition button is pressed the keyless entry antenna transmitter broadcasts a challenge within the passenger compartment to the key fob. If the response from the key fob via radio frequency (RF) is a valid response and all the security requirement are met the vehicles engine will start or be able to go into accessory mode.

Areas of high radio frequency (RF) traffic may cause an intermittent NO FOB DETECTED message. This is a normal condition. If the vehicle is parked in an area of high RF traffic, move vehicle before continuing with diagnostics.

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

Scan Tool Reference

Control Module References for Scan Tool Information

Important: This condition may be caused by low vehicle battery voltage. If the battery is not sufficiently charged (above 10 volts), the system will have difficulties detecting the fob and the NO FOBS DETECTED message will be displayed. Correct the low battery voltage condition to eliminate this condition.

1. With the vehicle locked, attempt to passively unlock and enter the vehicle by approaching the vehicle with a valid transmitter and pressing the door touch pad. The door should unlock and open.

⇒	If unable to enter the vehicle passively, refer to Keyless Entry System Inoperative .

2. While placing the keyless entry transmitter in various locations within the vehicle interior, verify the vehicle does not start.

⇒	If the vehicle starts, inspect for any sources of RF interference such as cell phone chargers, power supplies, etc. that would interrupt transmitter and antenna communication.

1. Ignition OFF, disconnect the harness connector at the back up keyless entry 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 RCDLR.

3. Ignition OFF, 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.
4. Ignition ON, verify the DMM captured and 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 RCDLR.

5. If all circuits test normal, test or replace the back up keyless entry antenna.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.