B1A72-01

B1A72-01-PASSIVE ENTRY ANTENNA 2 - GENERAL ELECTRICAL FAILURE

For a complete wiring diagram, refer to the Wiring Information.





Theory of Operation

The Passive Entry (PE) antenna units allow the transmitter within the Radio Frequency Hub (also known as the RF Hub) to communicate via Low Frequency (LF) radio transmission with a FOB with Integrated Key (FOBIK) that is located inside the vehicle or, at most, about 2 meters (6.5 feet) horizontally in all directions around the outside of the vehicle. The RF Hub uses communication through the antenna units to wake up and challenge a FOBIK that is within range in order to authenticate whether that FOBIK is valid (programmed) to the vehicle. The RF Hub communication with the FOBIK is on 20 kilohertz using Frequency-Shift Keying (FSK) modulation.

Each antenna unit has two dedicated connections to the RF Hub. One connection is the LF antenna output circuit, while the other connection Is the LF antenna return circuit. These circuits to each antenna unit are a twisted pair to help reduce the potential for induced electrical interference. The RF Hub microprocessor continuously monitors all of the antenna units and will store a Diagnostic Trouble Code (DTC) for any fault that it detects.

The hard wired inputs and outputs of the antenna units may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, the most reliable, efficient, and accurate means to diagnose the antenna units requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

- When Monitored:
At every Passive Entry or Keyless Go action.

- Set Condition:
Antenna is faulty, out of range, linear factor is too high or low and no other antennas have a short to battery or a short to ground condition.





Diagnostic Test

1. TEST FOR INTERMITTENT CONDITION

NOTE: If there are any antennas that have a Short to Ground or Short to Battery DTC, repair them before proceeding.

1. Turn the ignition on.
2. Using the scan tool, record and erase the DTCs.
3. With the scan tool, select: RF Hub, More Options and System Tests.
4. Perform the RF Hub LF Antenna Verification Tests.
5. With the scan tool, read the Active DTCs.

Does the scan tool display: B1A72-01-PASSIVE ENTRY ANTENNA 2 - GENERAL ELECTRICAL FAILURE as active?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals and correct pin tension.
- Perform the BODY VERIFICATION TEST. Body Verification Test .

2. ANTENNA OR MODULE
1. Turn the ignition off.
2. Disconnect the Passive Entry Antenna 2 connector.

NOTE: For antenna locations, Passive Entry Antenna - Description .

3. Replace Antenna 2 with a known good antenna. NOTE: For this test you could use one of the other antennas that does not have a DTC set against it.

4. Turn the ignition on.
5. Using the scan tool, record and erase the DTCs.
6. With the scan tool, select: RF Hub, More Options and System Tests.
7. Perform the RF Hub LF Antenna Verification Tests.
8. With the scan tool, read the Active DTCs.

Does the scan tool display: B1A72-01-PASSIVE ENTRY ANTENNA 2 - GENERAL ELECTRICAL FAILURE as active?

Yes

- Replace the RF Hub. Radio Frequency Module (RF Hub) - Removal.
- Perform the RADIO FREQUENCY HUB (RF HUB) VERIFICATION TEST. Vehicle Theft Security RF Hub Verification Test.

No

- Replace the Antenna. Passive Entry Antenna - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test .