System Check - Keyless Entry

Remote Keyless Entry System Check:

Remote Keyless Entry System Check (Part 1 Of 2):

Remote Keyless Entry System Check (Part 2 Of 2):

CIRCUIT DESCRIPTION
The Remote Keyless Entry Diagnostic System Check is an organized approach to identify problems associated with the Remote Function Actuation (RFA) system. This check must be the starting point for any RFA complaint, and will direct you to the next logical step in diagnosing the complaint. The RFA system and the Tire Pressure Monitor (TPM) system use the same receiver. Therefore, when a TPM system malfunction occurs, all diagnostic information (DTCs, input data, etc.) must be accessed through the RFA system. Understanding the RFA/TPM system and using the tables correctly will reduce diagnostic time and prevent unnecessary parts replacement.

DIAGNOSTIC AIDS
^ The following conditions may result in an intermittent operation of the RFA system with no DTC stored:
- Any condition which results in the interruption of power to the receiver
- Weak or rundown battery
- Out of range battery or ignition voltage Specification Normal battery or ignition voltage: 9.0-16.0 V.
- A loose or damaged ground(s)
- An open or shorted serial data line
^ An intermittent malfunction in the electronic system may be very difficult to detect and to accurately diagnose. The RFA tests for different malfunctions under different vehicle conditions. For this reason, a thorough test drive is often needed in order to repeat a malfunction. If the system malfunction is not repeated during the test drive, a good description of the complaint may be very useful in locating an intermittent fault condition. Faulty electrical connections or wiring causes most intermitting problems. When an intermitting condition is suspected, check the suspected circuits for the following conditions:
- Poor mating of connector halves or backed out terminals
- Improperly formed or damaged terminals
- Wire chafing
- Poor wire to terminal connections
- Dirty or corroded terminals
- Damage to connector bodies
^ Use the J 35616-A
^ When a RFA system malfunction is corrected, clear the receiver's diagnostic memory before road testing the vehicle in order to avoid reading the original DTC stored in the memory.
^ Exit all scan tool tests before cycling the ignition OFF to ON unless the scan tool instructions direct otherwise. Follow the operating instructions in the scan tool operator's manual. Failure to follow these instruction may set DTCs, cause vehicle system malfunctions, set false DTCs, or cause scan tool malfunctions.
^ Inspect the power door locks for proper operation. If the locks do not function properly, repair the locks before diagnosing the RFA system.
^ Inspect that the transmitter battery terminals are clean and are making good contacts with the battery.
^ Try a second transmitter, if available. If the second transmitter operates, remove the battery and install the battery in the original and perform the synchronizing transmitter procedure. Try the original transmitter again. If the original transmitter operates, replace the battery. If the original transmitter still does not work, replace the original transmitter.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table:
1. This test determines if communications can be established with the RFA system.
2. This test checks for any RFA system DTCs stored in the receiver's memory.
3. This test determines if communications can be established with other systems connected to the same serial data line.
4. This test checks the operation of the vehicle door lock system. The vehicle door lock system must be functioning properly before diagnosing the RFA system.
5. This test checks the receiver's power circuit. If the test lamp does not light, there is an open in CKT 540.
6. This test checks the receiver's ground circuit. If the test lamp does not light, there is an open in CKT 851.
7. This test checks for an open in the serial data line between the receiver and the Data link Connector (DLC) terminal, CKT 1045.