Diagnostic Instructions
Circuit/System Description
The keyless entry system is a vehicle entry device. The keyless entry will unlock the vehicle doors or open the rear compartment when a corresponding button on the keyless entry transmitter is pressed. This is accomplished by the keyless entry transmitter
sending a radio frequency to the remote control door lock receiver (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
J 43241 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.
Reference Information
Schematic Reference
Remote Function Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Keyless Entry System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Special Tools
J 43241 Keyless Entry Tester
Circuit/System Verification
Attempt to program the keyless entry transmitter, refer to
Transmitter Programming. The transmitter should program.
Circuit/System Testing
- Verify that the transmitter is the correct transmitter for the vehicle.
⇒ | If not the correct transmitter, replace the transmitter. |
- Verify the scan tool Remote Key parameter for the appropriate transmitter is Programmed.
- Place the transmitter on the test pad of the
J 43241 and press each transmitter button one at a time. The tester should sound a tone and illuminate a green light with each button press.
⇒ | If one or more buttons does not sound the tone and illuminate the green light, replace the transmitter battery and retest with the
J 43241 . If the condition continues after battery replacement, replace the
transmitter. |
- Operate the transmitter while observing the scan tool Remote Key Function parameter for the appropriate transmitter. The parameter should correspond with the function selected on the transmitter.
⇒ | If the parameter does not match the function selected on the transmitter, replace the transmitter. |
- Attempt to program the transmitter, refer to
Transmitter Programming. The transmitter should program.
⇒ | If the transmitter does not program, test the keyless entry coax and/or antenna (if equipped) for a short to ground or an open/high resistance. If the circuit tests normal, replace the RCDLR. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.