Keyless Entry System: Diagnosis Chevrolet Uplander I

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Starting Point - Keyless Entry

Begin the system diagnosis with Diagnostic System Check - Vehicle in Vehicle DTC Information. The Diagnostic System Check will provide the following information

1. The identification of the control modules which command the system
2. The ability of the control modules 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 Data List

The Keyless Entry Scan Tool Data List contains all of the keyless entry related parameters that are available on the scan tool. The parameters in the list are arranged in alphabetical order. The column, "Data List," indicates the location of the parameter within the scan tool menu selections. Use the Keyless Entry Scan Tool Data List as directed by a diagnostic table or in order to supplement the diagnostic procedures. Begin all of the diagnostic procedures with Diagnostic System Check - Vehicle in Vehicle DTC Information.

Use the Scan Tool Data List only after the following is determined

1. There is no published DTC procedure nor published symptom procedure for the customer concern.
2. The DTC or symptom diagnostic procedure indicated by the diagnostic system check does not resolve the customer concern.

The Typical Data Values are obtained from a properly operating vehicle under the conditions specified in the first row of the Scan Tool Data List table. Comparison of the parameter values from the suspect vehicle with the Typical Data Values may reveal the source of the customer concern.

Scan Tool Data List

Circuit Description

The remote control door lock receiver (RCDLR) communicates with the body control module (BCM) through the keyless entry serial data circuit. When any button on the keyless entry transmitter is pressed, the transmitter sends a signal to the RCDLR. The RCDLR sends a lock, unlock or panic alarm request to the BCM, depending on which button is pressed on the transmitter. The BCM receives the message and performs the appropriate function. The BCM also uses the keyless entry serial data circuit in order to communicate with the RCDLR when programming transmitters.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC B3101 Keyless Entry Data Link Circuit Range/Performance

Conditions for Running the DTC

1. The ignition is ON.
2. The system voltage is at least 9 volts and no more than 16 volts.
3. This condition can only occur during transmitter programming.

Conditions for Setting the DTC

The BCM does not receive an acknowledgment message from the RCDLR within 300 milliseconds of a second Programming Mode/Diagnostic Mode request.

Action Taken When the DTC Sets

The BCM stores DTC B3101 in memory.

Conditions for Clearing the DTC

1. A current DTC will clear when the fault is no longer present and the ignition switch is cycled.
2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.
3. A scan tool may be used to clear history and current DTCs.

Diagnostic Aids

1. Always begin diagnosis with the first DTC listed on the scan tool.
2. Perform a visual inspection for loose or poor connections at all related components.
3. If the DTC B3101 is a history DTC, the fault may be intermittent. Refer to «Testing for Intermittent Conditions and Poor Connections»(ref-241671-S27410119602006081100000) in Wiring Systems.

The remote control door lock receiver (RCDLR) communicates with the body control module (BCM) through the keyless entry serial data circuit. When any button on the keyless entry transmitter is pressed, the transmitter sends a signal to the RCDLR. The RCDLR sends a lock, unlock, rear release or panic alarm request to the BCM, depending on which button is pressed on the transmitter. The BCM receives the message and performs the appropriate function. The BCM also uses the keyless entry serial data circuit in order to communicate with the RCDLR when programming transmitters.

This diagnostic procedure supports the following DTC

DTC B3102 Keyless Entry Data Link Circuit Low

1. The ignition is ON.
2. The system voltage is at least 9 volts and no more than 16 volts.

1. The keyless entry serial data circuit is shorted to ground.
2. The above conditions must be met for approximately 300 milliseconds.

The keyless entry system will not operate.

1. A current DTC will clear when the fault is no longer present and the ignition switch is cycled.
2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.
3. A scan tool may be used to clear history and current DTCs.

The remote control door lock receiver (RCDLR) communicates with the body control module (BCM) through the keyless entry serial data circuit. When any button on the keyless entry transmitter is pressed, the transmitter sends a signal to the RCDLR. The RCDLR sends a lock, unlock, rear release or panic alarm request to the BCM, depending on which button is pressed on the transmitter. The BCM receives the message and performs the appropriate function. The BCM also uses the keyless entry serial data circuit in order to communicate with the RCDLR when programming transmitters.

This diagnostic procedure supports the following DTC

DTC B3103 Keyless Entry Data Link Circuit High

1. The system voltage is at least 9 volts and no more than 16 volts.
2. The BCM must be receiving a message from the RCDLR while in the program mode.

The BCM detects a short to voltage in the keyless entry serial data circuit.

The keyless entry system will not operate.

1. A current DTC will clear when the fault is no longer present and the ignition switch is cycled.
2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.
3. A scan tool may be used to clear history and current DTCs.

1. Always begin diagnosis with the first DTC listed on the scan tool.
2. Perform a visual inspection for loose or poor connections at all related components.
3. If the DTC B3103 is a history DTC, the fault may be intermittent. Refer to «Testing for Electrical Intermittents»(ref-241671-S23310108862006081100000) in Wiring Systems.

The remote control door lock receiver (RCDLR) communicates with the body control module (BCM) through the keyless entry serial data circuit. When any button on the keyless entry transmitter is pressed, the transmitter sends a signal to the RCDLR. The RCDLR sends a lock, unlock, rear release or panic alarm request to the BCM, depending on which button is pressed on the transmitter. The BCM receives the message and performs the appropriate function. The BCM also uses the keyless entry serial data circuit in order to communicate with the RCDLR when programming transmitters.

This diagnostic procedure supports the following DTC

DTC B3106 Keyless Entry Data Link Parity Error

The BCM detects an invalid message from the RCDLR (a message with a parity error).

The BCM stores DTC B3106 in memory.

1. A current DTC will clear when the fault is no longer present and the ignition switch is cycled.
2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.
3. A scan tool may be used to clear history and current DTCs.

DTC B3106

Symptoms - Keyless Entry

1. Perform «Diagnostic System Check - Vehicle»(ref-241670-S16610990062006081100000) in Vehicle DTC Information, before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to «Keyless Entry System Description and Operation»(ref-241691-S22882930082006081100000) .

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the Keyless Entry System. Refer to «Checking Aftermarket Accessories»(ref-241671-S33907418562006081100000) 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-241691-S29130843662006081100000)
2. «Keyless Entry System Inoperative»(ref-241691-S17027410332006081100000)