Contents Wiring diagrams Section: Door Locks & Anti-Theft Systems All sections

Keyless Entry System: Diagnosis Chevrolet Silverado 3500

Diagnostic Starting Point - Keyless Entry

Begin the system diagnosis with Diagnostic System Check - Remote Keyless Entry . The Diagnostic System Check will provide the following information

  1. The identification of the control module(s) which command the system
  2. The ability of the control module(s) to communicate through the serial data circuit
  3. The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Scan Tool Output Controls

Scan Tool Output ControlAdditional Menu SelectionsDescription
Special FunctionsProgram All Key FobsThe Passenger door module will erase all previously programmed key fobs and then program the first fob as Fob 1, the next fob as Fob 2,and any additional fobs as Fob 3 and Fob 4.
Special FunctionsProgram Individual Key FobThe Passenger door module will program a key fob to any one of 4 possible positions: Key Fob 1-4.

Scan Tool Output Controls

Scan Tool Data List

Scan Tool ParameterData ListUnits DisplayedTypical Data Value
Operating Conditions: Ignition ON, Engine OFF
Fob 1 BatteryPassenger Door Module DataOK, LowOK
Fob 2 BatteryPassenger Door Module DataOK, LowOK
Fob 3 BatteryPassenger Door Module DataOK, LowOK
Fob 4 BatteryPassenger Door Module DataOK, LowOK
Last Fob Button PressedPassenger Door Module DataLock, Unlock, PanicUnlock
Last FOB UsedPassenger Door Module DataFOB 1-4FOB 1
Fob 1 ProgrammedPassenger Door Module DataYes, NoYes
Fob 2 ProgrammedPassenger Door Module DataYes, NoYes
Fob 3 ProgrammedPassenger Door Module DataYes, NoNo
Fob 4 ProgrammedPassenger Door Module DataYes, NoNo

Remote Keyless Entry Scan Tool Data List

Symptoms - Keyless Entry

IMPORTANTThe following steps must be completed before using the symptom tables. Perform Diagnostic System Check - Remote Keyless Entry before using the Symptom Tables in order to verify that all of the following are true. There are no DTCs set. The control module(s) can communicate via the serial data link. Review the system operation in order to familiarize yourself with the system functions. Refer to Keyless Entry System Description and Operation .

Visual/Physical Inspection

  1. Inspect for aftermarket devices which could affect the operation of the Remote Keyless Entry System. Refer to «Checking Aftermarket Accessories»(ref-184114-S31353837752005082200000) in Wiring Systems.
  2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

  1. «Panic Mode Inoperative»(ref-184149-S25738174092005082200000)
  2. «Keyless Entry System Inoperative»(ref-184149-S07899028612005082200000)

Method 2 - Scan Tool Required, Program Individual Transmitter

IMPORTANTAll transmitters which are to be recognized by the PDM must be programmed in a single programming sequence. When using this program method, all previously programmed transmitters will be erased upon the receipt of the programming signal from the first transmitter. The order in which the transmitters are programmed will determine its numbering position within the PDM memory. The first transmitter programmed will be transmitter #1, and the second transmitter programmed will be transmitter #2. The number stamped on the transmitter case is for reference only; #2 can be programmed as #1, or vice versa. Additional unnumbered transmitters are also available.

Only use this option if you are certain which transmitter, #1-#4, is being replaced, or the new transmitter can be programmed into a previously unused position within the PDM memory.

  1. Install a scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. Use the scan tool in order to access the passenger door module Special Function menu.
  4. Select Program Individual Key Fob to program specific transmitters.
  5. Follow the directions on the scan tool in order to program the transmitter or transmitters.
  6. Operate the transmitter functions in order to verify correct system operation.

Method 3 - Scan Tool Required, Program All Transmitters

IMPORTANTAll transmitters which are to be recognized by the PDM must be programmed in a single programming sequence. When using this program method, all previously programmed transmitters will be erased upon the receipt of the programming signal from the first transmitter. The order in which the transmitters are programmed will determine its numbering position within the PDM memory. The first transmitter programmed will be transmitter #1, and the second transmitter programmed will be transmitter #2. The number stamped on the transmitter case is for reference only; #2 can be programmed as #1, or vice versa. Additional unnumbered transmitters are also available.
  1. Install a scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. Use the scan tool in order to access the passenger door module Special Function menu.
  4. Select Program All Key Fobs to clear the PDM memory.
  5. Follow the directions on the scan tool in order to program the transmitters.
  6. Operate the transmitter functions in order to verify correct system operation.

The keyless entry system is a supplementary vehicle entry device. Radio frequencies or discharged batteries may disable the system.

Keyless entry can operate the following components

  1. The door locks
  2. The interior lamps
  3. The parking lamps
  4. The headlamps
  5. The puddle lamps (if equipped)
  6. The horn

The keyless entry system has the following main components

  1. The transmitters
  2. The passenger door module (PDM)

The PDM communicates with the body control module (BCM) through the keyless entry serial data circuit. When you press a button on a transmitter, the transmitter sends a signal to the PDM. The PDM sends a request to the BCM and the BCM performs the appropriate function.