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

Keyless Entry System: Overview Cadillac STS I

Door Locks & Anti-Theft Systems 5 illustrations ~474 words

Keyless Entry Schematic Icons

Keyless Entry Schematic Icons Icon Icon Definition IMPORTANT: Twisted-pair wires provide an effective "shield" that helps protect sensitive electronic components from electrical interference. If the wires were covered with shielding, install new shielding. Refer to Splicing Twisted or Shielded Cable in Wiring Systems. In order to prevent electrical interference from degrading the performance of the connected components, you must maintain the proper specification when making any repairs to the twisted-pair wires shown : The wires must be twisted a minimum of 12 turns per 31 cm (12 in) as measured anywhere along the length of the wires The outside diameter of the twisted wires must not exceed 6.0 mm

Scheme 41

Scheme 41: Keyless Entry Schematic Icons

Scheme 42

Scheme 42: Keyless Entry Schematics

Scheme 43

Scheme 43

Scheme 44

Scheme 44: Keyless Entry Component Views
CalloutComponent Name
1The Keyless Entry Antenna Rear Compartment, located in the rear compartment area near the rear compartment lid latch
2The Keyless Entry Antenna Rear Window, located on the upper left area of the rear window
3The Keyless Entry Antenna-Headliner, located in the passenger area, beneath the headliner
4The LF door Handle Antenna, located within the LF exterior door handle
5The Keyless Entry Antenna, located inside the passenger compartment, within the center console
6The Keyless Entry Antenna-Backup, located in the passenger area, within the center console
7The RF door Handle Antenna, located within the RF exterior door handle
8The Remote Control Door Lock Receiver (RCDLR), located below the rear shelf

Scheme 45

Scheme 45
CalloutComponent Name
1Module Bracket Assembly
2Remote Control Door Lock Receiver (RCDLR)
3Rear Integration Module (RIM)
4Rear Object Sensor Control Module
5Rear Window Shelf

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: Verifies that DTC B3119 is a current DTC.
  2. 3: Verifies that the driver door handle is operating properly. A valid input from the driver door handle is required by the RCDLR to authenticate the antenna.
  3. 4: Testing for power and ground to the keyless entry antenna.
StepActionYesNo
Schematic Reference: Keyless Entry Schematics Connector End View Reference: Keyless Entry Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2IMPORTANT: To achieve service by pass mode, key ON, engine OFF, a programmed transmitter must be detected within the passenger compartment of the vehicle. Install a scan tool. Push and hold the ACC button for 5 seconds to achieve the service bypass mode, with the engine OFF. Select display DTCs function on the scan tool in the remote control door lock receiver (RCDLR) menu. Does the scan tool display DTC B3119 as a current DTC?Go to Step 3Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3With the scan tool, observe the driver door handle parameter in the driver door module (DDM) data list. Operate the driver exterior door handle. Does the driver door handle state display INACTIVE?Go to Power Door Latch Inoperative - Driver Door in DoorsGo to Step 4
4IMPORTANT: The voltage signal sent by the RCDLR to the passive antenna is a AC voltage signal. The DMM must be set on AC voltage setting to record the voltage pulse to the passive antenna. Use a DMM to record the voltage pulse using the MIN MAX setting to capture the AC voltage pulse to the passive antenna. Disconnect the keyless entry antenna-left at the LH exterior door handle. With the DMM measure/capture for an AC voltage signal between the keyless entry antenna low reference circuit and the signal circuit. With the scan tool, go to the RCDLR Special Functions menu. Select Right Door Handle Antenna. Authenticate the antenna using the scan tool. Was an AC voltage signal captured on the DMM?Go to Step 7Go to Step 5
5Test both the keyless entry antenna low reference and signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 6
6Inspect for poor connections at the RCDLR. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 8
7Inspect for poor connections at the keyless entry antenna - left. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 10
8Test the keyless entry antenna signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 9
9Replace the RCDLR. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 12
10Test both the keyless entry antenna signal and low reference circuit for a short to power. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 11
11Replace the keyless entry antenna - left. Refer to Door Handle Replacement - Front Outside in Doors. Did you complete the replacement?Go to Step 12
12Use the scan tool in order to clear the DTCs. Operate the vehicle within the conditions for running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 3System OK
IMPORTANT
To achieve service by pass mode, key ON, engine OFF, a programmed transmitter must be detected within the passenger compartment of the vehicle.
IMPORTANT
The voltage signal sent by the RCDLR to the passive antenna is a AC voltage signal. The DMM must be set on AC voltage setting to record the voltage pulse to the passive antenna. Use a DMM to record the voltage pulse using the MIN MAX setting to capture the AC voltage pulse to the passive antenna.

DTC B3119

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: Verifies that DTC B3120 is a current DTC.
  2. 3: Verifies that the passenger door handle is operating properly. A valid input from the passenger door handle is required by the RCDLR to authenticate the antenna.
  3. 4: Testing for power and ground to the keyless entry antenna.
StepActionYesNo
Schematic Reference: Keyless Entry Schematics Connector End View Reference: Keyless Entry Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2IMPORTANT: To achieve service by pass mode, key ON, engine OFF, a programmed transmitter must be detected within the passenger compartment of the vehicle. Install a scan tool. Push and hold the ACC button for 5 seconds to achieve the service bypass mode, with the engine OFF. Select display DTCs function on the scan tool in the remote control door lock receiver (RCDLR) menu. Does the scan tool display DTC B3120 as a current DTC?Go to Step 3Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3With the scan tool, observe the passenger door handle parameter in the passenger door module (PDM) data list. Operate the passenger exterior door handle. Does the passenger door handle state display INACTIVE?Go to Power Door Latch Inoperative - Passenger DoorGo to Step 4
4IMPORTANT: The voltage signal sent by the RCDLR to the passive antenna is a AC voltage signal. The DMM must be set on AC voltage setting to record the voltage pulse to the passive antenna. Use a DMM to record the voltage pulse using the MIN MAX setting to capture the AC voltage pulse to the passive antenna. Disconnect the keyless entry antenna - right at the exterior door handle. With the DMM measure/capture for an AC voltage signal between the keyless entry antenna signal circuit and the low reference circuit. With the scan tool, go to the RCDLR special functions menu. Select Right Door Handle Antenna Authenticate the antenna using the scan tool. Was an AC voltage signal captured on the DMM?Go to Step 7Go to Step 5
5Test both the keyless entry antenna signal and low reference circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 6
6Inspect for poor connections at the RCDLR. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 8
7Inspect for poor connections at the keyless entry antenna - right. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 10
8Test the keyless entry antenna signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 9
9Replace the RCDLR. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 12
10Test both the keyless entry antenna signal and low reference circuit for a short to power. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 11
11Replace the keyless entry antenna - right. Refer to Door Handle Replacement - Front Outside in Doors. Did you complete the replacement?Go to Step 12
12Use the scan tool in order to clear the DTCs. Operate the vehicle within the conditions for running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 3System OK
IMPORTANT
To achieve service by pass mode, key ON, engine OFF, a programmed transmitter must be detected within the passenger compartment of the vehicle.
IMPORTANT
The voltage signal sent by the RCDLR to the passive antenna is a AC voltage signal. The DMM must be set on AC voltage setting to record the voltage pulse to the passive antenna. Use a DMM to record the voltage pulse using the MIN MAX setting to capture the AC voltage pulse to the passive antenna.

DTC B3120

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: Verifies that DTC B3121 is a current DTC.
  2. 4: Verifies that the exterior rear compartment lid release pad is operating properly. A valid input from the lid release pad is required by the RCDLR to authenticate the antenna.
  3. 4: Testing for power and ground to the keyless entry antenna.
StepActionYesNo
Schematic Reference: Keyless Entry Schematics Connector End View Reference: Keyless Entry Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2IMPORTANT: To achieve service by pass mode, key ON, engine OFF, a programmed transmitter must be detected within the passenger compartment of the vehicle. Install a scan tool. Push and hold the ACC button for 5 seconds to achieve the service bypass mode, with the engine OFF. Select display DTCs function on the scan tool in the remote control door lock receiver (RCDLR) menu. Does the scan tool display DTC B3121 as a current DTC?Go to Step 3Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3With the scan tool, observe the trunk release switch parameter in the remote control door lock receiver (RCDLR) miscellaneous inputs data list. Operate the exterior rear compartment lid release pad. Does the trunk release switch state display INACTIVE?Go to Trunk Release Inoperative (Interior Release Inoperative ) or Trunk Release Inoperative (Exterior Release Inoperative) in Body Rear EndGo to Step 4
4IMPORTANT: The voltage signal sent by the RCDLR to the passive antenna is a AC voltage signal. The DMM must be set on AC voltage setting to record the voltage pulse to the passive antenna. Use a DMM to record the voltage pulse using the MIN MAX setting to capture the AC voltage pulse to the passive antenna. Disconnect the keyless entry antenna - rear compartment at the rear compartment latch area. With the DMM measure/capture for an AC voltage signal between the keyless entry antenna signal circuit and the low reference circuit. With the scan tool, go to the RCDLR special functions menu. Select Rear Fascia Antenna. Authenticate the antenna using the scan tool. Was an AC voltage signal captured on the DMM?Go to Step 7Go to Step 5
5Test both the keyless entry antenna signal and low reference circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 6
6Inspect for poor connections at the RCDLR. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 8
7Inspect for poor connections at the keyless entry antenna - rear compartment. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 10
8Test the keyless entry antenna signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 9
9Replace the RCDLR. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 12
10Test both the keyless entry antenna signal and low reference circuit for a short to power. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 10
11Replace the keyless entry antenna - rear compartment. Refer to Receiver, Antenna Replacement - Remote Control Door Lock and Theft Deterrent . Did you complete the replacement?Go to Step 12
12Use the scan tool in order to clear the DTCs. Operate the vehicle within the conditions for running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 3System OK
IMPORTANT
To achieve service by pass mode, key ON, engine OFF, a programmed transmitter must be detected within the passenger compartment of the vehicle.
IMPORTANT
The voltage signal sent by the RCDLR to the passive antenna is a AC voltage signal. The DMM must be set on AC voltage setting to record the voltage pulse to the passive antenna. Use a DMM to record the voltage pulse using the MIN MAX setting to capture the AC voltage pulse to the passive antenna.

DTC B3121

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: This step verifies that proper operation of the keyless entry console active antenna
StepActionValuesYesNo
Schematic Reference: Keyless Entry Schematics Connector End View Reference: Keyless Entry Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Install a scan tool. Place the keyless entry transmitter in the fob pocket located within the center console. In the RCDLR output controls menu, select Active Antenna Attempt to authenticate the Active Antenna Does the Active Antenna authenticate?Go to Testing for Intermittent Conditions and Poor Connections in Wiring SystemsGo to Step 3
3At the RCDLR, measure the voltage of the Keyless Entry Active Antenna Supply Voltage circuit with a DMM. Does the voltage equal the specified value?0 VGo to Step 4Go to Step 7
4At the RCDLR, measure the voltage of the Keyless Entry Active Antenna Data Signal circuit with a DMM. Does the voltage equal the specified value?0 VGo to Step 5Go to Step 8
5At the RCDLR, measure the voltage of the Keyless Entry Active Antenna Clock Signal circuit with a DMM. Does the voltage equal the specified value?0 VGo to Step 9Go to Step 6
6At the RCDLR, measure the voltage of the Keyless Entry Active Antenna Low Reference circuit with a DMM. With the scan tool, go to the Active Antenna output control in the RCDLR special functions menu. While viewing the DMM, attempt to authenticate the Active Antenna. Does the voltage transition to the specified value?OLGo to Step 11Go to Step 10
7Test the Keyless Entry Active Antenna Supply Voltage circuit for one of the following: Short to ground Short to power Open Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 11
8Test the Keyless Entry Active Antenna Data Signal circuit for one of the following: Short to ground Short to power Open Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 11
9Test the Keyless Entry Active Antenna Clock Signal circuit for one of the following: Short to ground Short to power Open Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 12
10Test the Keyless Entry Active Antenna Low Reference circuit for one of the following: Short to ground Short to power Open Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 12
11Inspect for poor connections at the RCDLR. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 13
12Inspect for poor connections at the Keyless Entry Active Antenna. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 14
13Replace the RCDLR. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 15
14Replace the Keyless Entry Active Antenna. Refer to Receiver, Antenna Replacement - Remote Control Door Lock and Theft Deterrent . Did you complete the replacement?Go to Step 15
15Use the scan tool in order to clear the DTCs. Operate the vehicle within the conditions for running the DTC, as specified in the supporting text. Does the DTC reset?System OKGo to Step 2

DTC B3122

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: This step verifies that DTC B3123 is a current DTC.
  2. 3: This step tests the function of the headliner antenna. Because the console antenna and headliner antenna share a drive within the RCDLR, the console antenna must be disconnected to properly check functionality of the headliner antenna.
  3. 4: This step verifies the RCDLR is sending out the required AC voltage signal to the headliner antenna.
  4. 5: This step verifies the RCDLR is sending out the required AC voltage signal to the console antenna.
StepActionYesNo
Schematic Reference: Keyless Entry Schematics Connector End View Reference: Keyless Entry Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2IMPORTANT: To achieve service by pass mode (key ON, engine OFF) a programmed transmitter must be detected within the passenger compartment of the vehicle. Install a scan tool. Push and hold the ACC button for 5 seconds to achieve the service bypass mode, with the engine OFF. Select display DTCs function on the scan tool in the remote control door lock receiver (RCDLR) menu. Does the scan tool display DTC B3123 as a current DTC?Go to Step 3Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3IMPORTANT: The ignition start button must be pressed to produce the voltage pulse to the passive antenna. Disconnect the console antenna at the center console. With the keyless entry transmitter held near the headliner antenna, press the ignition start button. Does the vehicle start?Go to Step 5Go to Step 4
4IMPORTANT: The voltage signal sent by the RCDLR to the passive antenna is an A/C voltage signal. The DMM must be set on A/C voltage setting to record the voltage pulse to the passive antenna. Use a DMM to record the voltage pulse using the MIN MAX setting to capture the A/C voltage pulse to the passive antenna. The ignition start button must be pressed to produce the voltage pulse to the passive antenna. Disconnect the headliner antenna. With the DMM measure/capture for an A/C voltage signal between the keyless entry signal circuit and the low reference circuit. Press the ignition start button. Was an A/C voltage signal captured on the DMM?Go to Step 9Go to Step 6
5IMPORTANT: The voltage signal sent by the RCDLR to the passive antenna is an A/C voltage signal. The DMM must be set on A/C voltage setting to record the voltage pulse to the passive antenna. Use a DMM to record the voltage pulse using the MIN MAX setting to capture the A/C voltage pulse to the passive antenna. The ignition start button must be pressed to produce the voltage pulse to the passive antenna. With the DMM, measure/capture for an A/C voltage signal between the console keyless entry antenna signal circuit and the low reference circuit. Press the ignition start button. Was an A/C voltage signal captured on the DMM?Go to Step 10Go to Step 7
6Test the headliner keyless entry antenna signal circuit and low reference circuit for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 8
7Test the console keyless entry antenna signal circuit and low reference circuit for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 8
8Inspect for poor connections at the RCDLR. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 11
9Inspect for poor connections at the headliner antenna. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 12
10Inspect for poor connections at the console antenna. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 13
11Replace the RCDLR. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 14
12Replace the headliner antenna. Refer to Receiver, Antenna Replacement - Remote Control Door Lock and Theft Deterrent . Did you complete the replacement?Go to Step 14
13Replace the console antenna. Refer to Receiver, Antenna Replacement - Remote Control Door Lock and Theft Deterrent . Did you complete the replacement?Go to Step 14
14Use the scan tool in order to clear the DTCs. Operate the vehicle within the conditions for running the DTC, as specified in the supporting text. Does the DTC reset?Go to Step 3System OK
IMPORTANT
To achieve service by pass mode (key ON, engine OFF) a programmed transmitter must be detected within the passenger compartment of the vehicle.
IMPORTANT
The ignition start button must be pressed to produce the voltage pulse to the passive antenna.
IMPORTANT
The voltage signal sent by the RCDLR to the passive antenna is an A/C voltage signal. The DMM must be set on A/C voltage setting to record the voltage pulse to the passive antenna. Use a DMM to record the voltage pulse using the MIN MAX setting to capture the A/C voltage pulse to the passive antenna. The ignition start button must be pressed to produce the voltage pulse to the passive antenna.
IMPORTANT
The voltage signal sent by the RCDLR to the passive antenna is an A/C voltage signal. The DMM must be set on A/C voltage setting to record the voltage pulse to the passive antenna. Use a DMM to record the voltage pulse using the MIN MAX setting to capture the A/C voltage pulse to the passive antenna. The ignition start button must be pressed to produce the voltage pulse to the passive antenna.

DTC B3123

Unlock All Doors - Second Operation - Active

Momentarily press the transmitter UNLOCK button a second time, within 4 seconds of the first press, to perform the following functions

Unlock the remaining doors.