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
| - | Weak transmitter battery |
| - | 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 intermittent 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 |
| • | If the transmitter range decreases or the transmitter does not operate, check for the following conditions: |
| • | Use the J 35616 Connector Test Adapter Kit whenever a diagnostic procedure requests terminal inspection or probing. Using the adapter ensures no damage to the terminal will occur, and will give an idea of whether contact tension is sufficient. |
| - | Check if battery replacement is necessary |
| - | Check for proper range (Rainy or snowy weather decreases range) |
| - | Check for obstructions (other vehicles or objects will decrease range) |
| - | Electrical interference (cellular phones, power lines, radio towers, garage door openers, etc.) |
| - | The transmitter is not programmed or synchronized to the vehicle |
| • | 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. |
| • | Inspect the power door locks and hatch/trunk release functions for proper operation. If the locks and/or hatch/trunk release do not function properly, repair them 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:
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This test determines if communications can be established with the RFA system.
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This test checks for communication DTCs stored in the RFA system (communication DTCs begin with the letter U). Communication DTCs must be diagnosed and corrected first before diagnosing any other DTCs.
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This test checks for any RFA system DTCs stored in the receiver's memory.
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This test determines if communications can be established with other systems connected to the same serial data line.
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This test checks the operation of the transmitter in both the manual and passive positions. Refer to Keyless Entry System Description for transmitter operation.
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This test checks the receiver's power circuit. If the test light does not light, there is an open in CKT 540.
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This test checks the receiver's ground circuit. If the test light does not light, there is an open in CKT 851.
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This test checks for an open in the serial data line between the receiver and the DLC terminal, CKT 1045.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Does the scan tool communicate with the RFA system? | -- | |||
Are any communication DTCs stored? | -- | |||
Check for any RFA DTCs. Refer to Diagnostic Trouble Code (DTC) List/Type . Are any of these DTCs stored? | -- | Go to the Applicable DTC Table | ||
Attempt to establish communications with the other systems connected to the same serial data line (PCM, BCM, ABS, IPC, etc.). Does the scan tool communicate with any other system? | -- | |||
Operate the transmitter through all button and switch positions. Refer to Keyless Entry System Description . Is the transmitter functioning properly? | -- | System OK | ||
Is the test light ON? | -- | |||
Is the test light ON? | -- | |||
Check for continuity between the RFA receiver connector terminal D (harness side) and DLC connector terminal 2. Is there continuity? | -- | |||
9 |
Is the replacement complete? | -- | -- | |
10 |
Are the repairs complete? | -- | -- | |
11 | Locate and repair the open in CKT 1045. Is the repair complete? | -- | -- | |
12 | Locate and repair the open in CKT 851. Is the repair complete? | -- | -- | |
13 |
Are all repairs complete? | -- | System OK | -- |
