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Home >> GMC >> 2021 >> Acadia SL >> Repair and Diagnosis >> Body & Frame >> Door Locks >> Keyless Entry System And Remote Functions >> Diagnostic Information and Procedures >> Keyless Entry System Malfunction >> Circuit/System Testing
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Circuit/System Testing

NOTE:

The passive entry system unlocking function can be disabled through the transmitter, the center stack, or an SPS programming event in the keyless entry control module. The center stack displays the status of the feature. Refer to owners manual for more information.

Remote Control Door Lock Receiver Malfunction

  1. Ignition OFF and all vehicle systems OFF, scan tool disconnected, disconnect the harness connector at the K77 Remote Control Door Lock Receiver It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 30 Ω between the low reference circuit terminal 4 and ground.
    • If 30 Ω or greater 
    1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
    2. Test for less than 2 Ω in the low reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
    • Go to next step: If less than 30 Ω 
  3. Ignition ON.
  4. Test for greater than 11.5 V between the B+ circuit terminal 1 and ground.
    • If 11.5 V or less 
    1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the B+ circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If Infinite resistance.
    3. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
    • Go to next step: If greater than 11.5 V 
  5. Test for 0.001 - 12 V between the serial data circuit terminal 2 and ground.
    • If less than 0.001 V 
    1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the serial data circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the serial data circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
    • If greater than 12 V 
    1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module, ignition ON.
    2. Test for less than 0.001 V between the serial data circuit and ground.
      • If 0.001 V or greater, repair the short to voltage on the circuit.
      • If less than 0.001 V, replace the K9 Body Control Module.
    • Go to next step: If between 0.001 - 12 V 
  6. Ignition OFF, disconnect the X8 harness connectors at the K9 Body Control Module, ignition ON.
  7. Test for less than 0.001 V between the K9 Body Control Module serial data circuit terminal 27 X2 and ground.
    • If 0.001 V or greater 

      Repair the short to voltage on the circuit.

    • Go to next step: If less than 0.001 V 
  8. Ignition OFF.
  9. Test for infinite resistance between the K9 Body Control Module serial data circuit terminal 27 X2 and ground.
    • If less than infinite resistance 

      Repair the short to ground on the circuit.

    • Go to next step: If infinite resistance 
  10. Test for less than 2 Ω between the K9 Body Control Module serial data circuit terminal 27 X2 and the K77 Remote Control Door Lock Receiver serial data circuit terminal 2.
    • If 2 Ω or greater 

      Repair the open/high resistance in the circuit.

    • Go to next step: If less than 2 Ω 
  11. Replace the K77 Remote Control Door Lock Receiver.
  12. Verify the keyless entry functions operate.
    • If the keyless entry functions do not operate 

      Replace the K9 Body Control Module

    • Go to next step: If the keyless entry functions operate 
  13. All OK.
NOTE:

The passive entry system unlocking function can be disabled through the transmitter, the center stack, or an SPS programming event in the keyless entry control module. The center stack displays the status of the feature. Refer to owners manual for more information.

Keyless Entry Antenna Malfunction

  1. Verify the scan tool Exterior Driver Door Handle Switch, Exterior Passenger Door Handle Switch, and Trunk Lid Exterior Unlatch Switch parameters change between Active and Inactive while operating their respective exterior door handle/rear closure touch pad.
    • Go to next step: If all of the parameters change 
  2. All OK.
  3. Verify that DTC B3119, B3120, B3121, B3122, B3123, or B3124 is not set.
    • Go to next step: If none of the DTCs are set 
    NOTE:

    Before using the RF Tool to detect antenna signals verify the location of the antenna on the vehicle for proper orientation and distance of the tool.

  4. To verify RF operation place the EL-52545  and the transmitter together while standing 3 meters (15 feet) from the vehicle and press the transmitter unlock button.
  5. Verify the 125 kHz frequency signal output displays at least 20%.
    • If the 125 kHz frequency signal displays 

      All OK, this antenna is functioning. Refer back to the Circuit/System Verification to identify a different likely cause or an intermittent condition.

    • Go to next step: If the 125 kHz frequency signal does not display. 
  6. Ignition OFF, disconnect the harness connector at the appropriate T10 Keyless Entry Antenna that is related to the fault condition, ignition ON.
  7. Test for less than 1 V between the signal circuit terminal 1 and ground.
    • If 1 V or greater 
    1. Ignition OFF, disconnect the harness connector at the K84 Keyless Entry Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K84 Keyless Entry Control Module.
    • Go to next step: If less than 1 V 
    8. NOTE:

    When using the MIN MAX function, autorange on the DMM may not function properly. To ensure accurate test results, turn off autorange and manually set the DMM range to 000.0 V.

  8. Ignition OFF, install a DMM between the signal circuit terminal 1 and ground. Set the DMM to capture DC voltage using the MIN MAX function. Turn off autorange and manually set the DMM range to 000.0 V.
  9. Lock the vehicle doors using the keyless entry transmitter. Activate the antenna by operating the appropriate exterior door handle/rear closure touch pad.
  10. Verify the MAX voltage captured by the DMM is greater than 1 V.
    • If 1 V or less 
    1. Ignition OFF, disconnect the harness connector at the K84 Keyless Entry Control Module.
    2. Test for infinite resistance between the signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K84 Keyless Entry Control Module.
    • Go to next step: If greater than 1 V 
  11. Test for less than 1 V between the low reference circuit terminal 2 and ground.
    • If 1 V or greater 
    1. Ignition OFF, disconnect the harness connector at the K84 Keyless Entry Control Module, ignition ON.
    2. Test for less than 1 V between the low reference circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K84 Keyless Entry Control Module.
    • Go to next step: If less than 1 V 
    12. NOTE:

    When using the MIN MAX function, autorange on the DMM may not function properly. To ensure accurate test results, turn off autorange and manually set the DMM range to 000.0 V.

  12. Install a DMM between the signal circuit terminal 1 and the low reference circuit terminal 2. Set the DMM to capture DC voltage using the MIN MAX function. Turn off autorange and manually set the DMM range to 000.0 V.
  13. Lock the vehicle doors using the keyless entry transmitter. Activate the antenna by operating the appropriate exterior door handle/rear closure touch pad.
  14. Verify the MAX voltage captured by the DMM is greater than 1 V.
    • If 1 V or less 
    1. Ignition OFF, disconnect the harness connector at the K84 Keyless Entry Control Module.
    2. Test for infinite resistance between the low reference circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the low reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K84 Keyless Entry Control Module.
    • Go to next step: If greater than 1V 
  15. Replace the appropriate T10 Keyless Entry Antenna.
  16. Lock the vehicle doors using the keyless entry transmitter. Activate the antenna by operating the appropriate exterior door handle/rear closure touch pad.
  17. Verify that the door/rear compartment unlocks and opens when the exterior door handle/rear closure touch pad is operated.
    • If the door/rear compartment does not unlock and open 

      Replace the K84 Keyless Entry Control Module.

    • Go to next step: If the door/rear compartment unlocks and opens 
  18. All OK.
NOTE:

The passive entry system unlocking function can be disabled through the transmitter, the center stack, or an SPS programming event in the keyless entry control module. The center stack displays the status of the feature. Refer to owners manual for more information.

Keyless Entry Transmitter Malfunction

  1. Ignition ON.
  2. Verify that DTC B3119, B3120, B3121, B3122, B3123, or B3124 is not set.
    • Go to next step: If none of the DTCs are set 
  3. Verify the Tire Pressure Monitoring System is functioning by adding air to one tire to see the air pressure display increase.
    • Go to next step: If the pressure increases 
  4. Verify the VIN information for the vehicle transmitter is correct using the EL-52545  .
    • If the VIN is incorrect 

      This transmitter is not for this vehicle, it may already be programmed to work with a different vehicle but cannot be programmed to this vehicle.

    • Go to next step: If the VIN is correct 
  5. Verify the frequency of the transmitter matches the frequency of the tire pressure monitoring system and the remote control door lock receiver using the EL-52545  .
    • If the transmitter frequency is incorrect 

      Replace the vehicle transmitter.

    • Go to next step: If the transmitter frequency is correct 
  6. Verify the part number information for the vehicle transmitter is correct using the EL-52545  .
    • If the vehicle transmitter part number is incorrect 

      Replace the vehicle transmitter.

    • Go to next step: If the vehicle transmitter part number is correct 
  7. Verify the transmitter output is above 20% on the EL-52545  signal strength meter by pressing a button on the transmitter ten times.
    • If the transmitter output is lower than 20% 

      Replace the transmitter battery.

      NOTE:

      Before replacing the transmitter, inspect the transmitter battery contacts for any corrosion or damage. If no corrosion or damage is found, replace the transmitter battery and retest before replacing the transmitter.

    • Go to next step: If the transmitter output is higher than 20% 
  8. Using the scan tool read the number of transmitters learned in the K9 Body Control Module. Using the EL-52545  read the number of transmitters learned in the transmitter.
    • Go to next step: If the transmitters learned is equal to the number programmed 
  9. Using the EL-52545  verify the transmitter is responding to the antenna by placing the transmitter next to the EL-52545  and pressing the start/stop button. The EL-52545  should display a high frequency (315 MHz or 433 MHz) reading when the start/stop button is pressed.
    1. Using the EL-52545  verify the transmitter is responding to the antenna by placing the transmitter next to the EL-52545  and pressing the start/stop button. The EL-52545  should display a high frequency (315 MHz or 433 MHz) reading when the start/stop button is pressed.
      • If the high frequency (315 MHz or 433 MHz) does not display. Replace the vehicle transmitter
    • Go to next step: If the high frequency (315 MHz or 433 MHz) does display 
  10. Verify the scan tool Exterior Driver Door Handle Switch, Exterior Passenger Door Handle Switch, and Trunk Lid Exterior Unlatch Switch parameters change between Active and Inactive while operating their respective exterior door handle/rear closure touch pad.
    • Go to next step: If all of the parameters change 
  11. Lock the vehicle using the keyless entry transmitter.
  12. Verify that each door and the rear compartment unlocks and opens by approaching the vehicle with a valid transmitter and operating their respective exterior door handle/rear closure touch pad.
    • If both doors and the rear compartment do not unlock/unlatch and open 

      Refer to Remote Control Door Lock Receiver Malfunction in Circuit/System Testing above.

    • If only one door or the rear compartment does not unlock/unlatch and open 

      Refer to Keyless Entry Antenna Circuit Malfunction in Circuit/System Testing above.

    • Go to next step: If both doors and the rear compartment unlocks/unlatches and opens 
  13. All OK.
  14. The concern may be caused by temporary RF interference. Discuss the conditions in which the concern occurs with the customer. 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.
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