For 1990-2009 cars
Keyless Entry Component Views
Keyless Entry Schematics

### Circuit Description

The Remote Keyless Entry Diagnostic System Test is an organized approach to identifying conditions associated with the remote function actuation (RFA) system. This test must be the starting point for any RFA complaint. The test 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 cause an intermittent operation of the RFA system with no DTC stored:

- | Any condition that causes interruption of power to the receiver

- | A weak or rundown battery

- | An out of range battery or ignition voltage

Specification
The normal battery or ignition voltage is 9.0-16.0 volts.

- | Any loose or damaged grounds

- | An open or shorted serial data line

• | An intermittent malfunction in the electronic system may be very difficult to detect and 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 intermittent conditions. When you suspect an intermittent condition, test 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 .

• | When an RFA system malfunction is corrected, clear the receiver's diagnostic memory before you road test the vehicle. This action prevents reading the original DTC stored in the memory.

• | Exit all of the 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 correct operation. If the locks do not operate correctly, repair the locks before you diagnose the RFA system.

• | Verify 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 the system correctly, remove the battery and install the battery in the first transmitter. Perform the synchronizing transmitter procedure. Try the first transmitter again. If the first transmitter operates the system correctly, replace the battery. If the first transmitter still does not operate correctly, replace the transmitter.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Operate the power door lock switches to the LOCK and UNLOCK positions. Do the power door locks operate with the door switches? | -- | Go to Step 2 | Go to Power Door Locks System Check in Doors
2 | Inspect the door lock fuse J in the LH instrument panel wiring harness junction block. Is the fuse open? | -- | Go to Step 15 | Go to Step 3
3 |

1. Connect the scan tool.
2. Turn the ignition switch to the ON position.
3. Select DIAGNOSTICS.
4. Select DIAGNOSTIC CIRCUIT CHECK.
5. Select CLASS 2 MESSAGE MONITOR.

Are the BCM and RFA modules listed as ACTIVE?

--

Go to Step 4

Go to Diagnostic System Check - Data Link Communications in Data Link Communications

4 | Select CLASS 2 DTC CHECK on the scan tool. Are there any BCm or RFA DTCs? | -- | Go to Door Lock Inoperative with Transmitter - All | Go to Step 5
5 | Activate the door lock switches with all of the doors closed. Do the doors lock and unlock? | -- | Go to Step 6 | Go to Step 7
6 | Resynchronize the keyless entry transmitter. Refer to Transmitter Synchronization . Do the doors lock and unlock using the transmitter? | -- | System OK | Go to Step 11
7 |

1. Select RFA DATA DISPLAY - FOB INFORMATION on the scan tool.
2. Press the LOCK and UNLOCK buttons on the keyless entry transmitter.

Does the status change?

--

Go to Step 8

Go to Step 13

8 | Lock and unlock the door locks using the BCM SPECIAL FUNCTIONS option on the scan tool. Do the door locks operate? | -- | Go to Step 9 | Go to Step 12
9 |

1. Select RFA SPECIAL FUNCTIONS on the scan tool.
2. Select PROGRAM KEY FOBs.

Did the system reprogram correctly?

--

Go to Step 10

Go to Step 14

10 | Resynchronize the system with a known good transmitter. Refer to Transmitter Synchronization . Did the system resynchronize correctly? | -- | System OK | Go to Door Lock Inoperative with Transmitter - All
11 |

1. Replace the transmitter battery. Refer to Transmitter Battery Replacement .
2. Resynchronize the transmitter. Refer to Transmitter Synchronization .

Do the doors lock and unlock?

--

System OK

Go to Step 7

12 |

1. Replace the body control module (BCM). Refer to Body Control Module Replacement in Body Control System.
2. Reprogram the BCM with the current calibrations. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Is the repair complete?

--

Go to Step 7

--

13 | Replace the keyless entry transmitter. Is the repair complete? | -- | Go to Step 6 | --
14 | Replace the RFA module. Refer to Receiver Replacement . Is the repair complete? | -- | Go to Step 9 | --
15 | Repair the open circuit in CKT 1040. Is the repair complete? | -- | System OK | --