LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 2007 >> STS Base, 4.6 A, AWD >> Repair and Diagnosis >> Accessories & Equipment >> Anti-Theft Systems >> Keyless Entry System And Remote Functions >> Diagnostic Information and Procedures >> DTC B3120 >> Test Description

Test Description

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.
DTC B3120

Step Action Yes No
Schematic Reference: Remote Function Schematics 
Connector End View Reference: Remote Function Connector End Views 
1 Did you perform the Diagnostic System Check - Vehicle? Go to Step 2  Go to Diagnostic System Check - Vehicle
2 
IMPORTANT: To achieve service by pass mode, key ON, engine OFF, a programmed transmitter must be detected within the passenger compartment of the vehicle.
  1. Install a scan tool.
  2. Push and hold the ACC button for 5 seconds to achieve the service bypass mode, with the engine OFF.
  3. 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 3  Go to Testing for Intermittent Conditions and Poor Connections
3 
  1. With the scan tool, observe the passenger door handle parameter in the passenger door module (PDM) data list.
  2. Operate the passenger exterior door handle.
Does the passenger door handle state display INACTIVE?		 Go to Power Door Latch Inoperative - Passenger Door Go to Step 4 
4 
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.
  1. Disconnect the keyless entry antenna - right at the exterior door handle.
  2. With the DMM measure/capture for an AC voltage signal between the keyless entry antenna signal circuit and the low reference circuit.
  3. With the scan tool, go to the RCDLR special functions menu. Select Right Door Handle Antenna
  4. Authenticate the antenna using the scan tool.
Was an AC voltage signal captured on the DMM?		 Go to Step 7  Go to Step 5 
5 Test both the keyless entry antenna signal and low reference circuit for an open. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 12  Go to Step 6 
6 Inspect for poor connections at the RCDLR. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 12  Go to Step 8 
7 Inspect for poor connections at the keyless entry antenna - right. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 12  Go to Step 10 
8 Test the keyless entry antenna signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 12  Go to Step 9 
9 Replace the RCDLR. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 Go to Step 12  -
10 Test both the keyless entry antenna signal and low reference circuit for a short to power. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 12  Go to Step 11 
11 Replace the keyless entry antenna - right. Refer to Front Side Door Outside Handle Replacement .
Did you complete the replacement?		 Go to Step 12  -
12
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the conditions for running the DTC as specified in the supporting text.
Does the DTC reset?		 Go to Step 3  System OK
scientia non olet · About LEMON Manuals