Colorado 4WD V8-5.3L (2010)
Circuit/System Description
The keyless entry system is a vehicle entry device. The keyless entry will unlock the vehicle doors when a corresponding button on the keyless entry
transmitter is pressed. This is accomplished by the key fob sending a radio frequency to the body control module (BCM). The signal is received by an
internal antenna located within the BCM. The BCM interprets the signal and activates the requested function. 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. An
incorrect transmitter may pass the test, but it will not activate the keyless entry system.
Reference Information
Schematic Reference
Door Lock/Indicator Schematics (See: Body and Frame/Locks/Diagrams/Electrical Diagrams)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Keyless Entry System Description and Operation (See: Description and Operation)
Electrical Information Reference
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Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
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Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Connector
Repairs/Connector Repairs)
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Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
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Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Special Tools
J 43241 Keyless Entry Tester
Circuit/System Verification
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 J 43241 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 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.
3. Verify the scan tool No. of Fobs Programmed parameter is greater than Fob 0.
‹› If not greater than the specified value, program the transmitter. Refer to Remote Control Door Lock Transmitter Programming (See: Testing
and Inspection/Programming and Relearning/Remote Control Door Lock Transmitter Programming).
4. Operate the transmitter while observing the scan tool Door Lock Output and Door Unlock Output parameters. The parameter should correspond
with the function selected on the transmitter.
‹› If the parameter does not match the function selected on the transmitter, program the transmitter and retest. Refer to Remote Control Door
Lock Transmitter Programming (See: Testing and Inspection/Programming and Relearning/Remote Control Door Lock Transmitter
Programming). If the condition continues after transmitter programming, replace the transmitter.