Keyless Entry System Inoperative

Keyless Entry System Inoperative

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

Circuit/System Description

The keyless entry system is a vehicle entry device. The keyless entry will unlock/unlatch the vehicle doors or open the rear gate when a corresponding button on the key fob is pressed. This is accomplished by the key fob sending a radio frequency to the remote control door lock receiver (RCDLR). The signal is received by the RCDLR via an internal antenna located within the RCDLR. The RCDLR interprets the signal and activates the requested function via a message over the GMLAN serial data line. A low transmitter battery or radio frequency (RF) interference from aftermarket devices such as 2-way radios, power inverters, cellular phone chargers, computers, etc. may cause a system malfunction. High RF traffic areas, such as gas stations which use pay-at-the-pump RF transponders, may also cause interference that could lead to a malfunction.

Diagnostic Aids

For the J43241 Keyless Entry Tester, inspect the keyless entry transmitter part number to determine that it is the correct model for the vehicle. A wrong model transmitter may pass the test, but it will not activate the vehicle remote system.

Circuit/System Testing

1. Verify that the transmitter is the correct transmitter for the vehicle.

• If not the correct transmitter, replace the transmitter.

2. Place the transmitter on the test pad of the J43241 and press each button of the transmitter one at a time. The tester should sound a tone and illuminate a green light when each button is pressed.

• If none of the buttons sounds the tone and illuminates the green light, replace the battery.
• If one or more of the buttons sounds the tone and illuminates the green light, replace the transmitter.

3. Operate the transmitter within the range of the vehicle. All of the keyless entry functions should operate normally.

• If not all of the functions operate normally, program the transmitter.

4. Ignition OFF, disconnect the harness connector at the RCDLR.
5. Ignition OFF, test for less than 1.0 ohm of resistance between the ground circuit and ground.

• If greater than 1.0 ohm, test the ground circuit for an open/high resistance.

6. Ignition ON, verify that a test lamp illuminates between the battery positive voltage circuit and ground.

• If the test lamp does not illuminate, repair the voltage supply circuit for a short to ground or an open/high resistance.

7. If all circuits test normal, test or replace the RCDLR module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Transmitter Programming for transmitter programming
* Control Module References for RCDLR replacement, setup, and programming