FixVault
Home › Chevrolet › 2021 › Traverse LS, FWD › Repair and Diagnosis › External Pages › Different car › Section 44 (Supplemental Restraints System) › Diagnostic Information and Procedures › DTC B1491 › Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2020 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
    NOTE:
    • Refer to: SIR Service Precautions 
    • inspect the terminals of the following components and connectors for damage or corrosion and repair or replace as necessary:
      • B61P Seat Belt Tension Sensor - Passenger
      • K85P Restraint Occupant Classification System Module - Passenger
      • Inline Harness Connector
    • The connector position assurance (CPA) should seat with an audible and/or tactile click. The CPA isolates the shorting-bars within the connector allowing the deployment circuit to operate properly.
    • If the condition is intermittent, wiggle the related wiring harnesses and connectors, with the ignition/vehicle on or engine running, while monitoring the scan tool circuit status parameters for the component. The parameters will display if there is a condition with the circuit or a connection.
    • If the condition is intermittent or cannot be duplicated, disconnect the connectors and add dielectric grease or lubricant (Nyogel 760G or equivalent, meeting GM specification 9986087). This procedure will correct the high resistance condition due to terminal fretting corrosion.
      • B61P Seat Belt Tension Sensor - Passenger & Harness Connector
      • K85P Restraint Occupant Classification System Module - Passenger & Harness Connector
  1. Ignition/Vehicle & All vehicle systems OFF
  2. Disconnect the B61P Seat Belt Tension Sensor - Passenger
  3. Test for less than 10 Ω between low reference circuit terminal 1 and ground
    • If 10 Ω or greater 
    1. Test circuit 3946 for an open.
      • If an open circuit is found, repair the fault on the circuit.
      • Go to next step: If an open circuit is found
    2. Replace the K85P Restraints Occupant Classification System Control Module
    • Go to next step: If less than 10 Ω 
  4. Ignition On / Vehicle In Service Mode
  5. Test for less than 6 V between the test points: Signal circuit terminal 2 and Ground.
    • If 6 V or greater 
    1. Ignition/Vehicle & All vehicle systems OFF
    2. Disconnect the electrical connector K85P Restraint Occupant Classification System Module - Passenger
    3. Ignition ON / Vehicle In Service Mode
    4. Test Circuit 3947 for short to voltage
      • If short to voltage is found, repair the fault on the circuit.
      • Go to next step: If short to voltage is not found
    5. Replace K85P Restraint Occupant Classification System Module - Passenger
    • Go to next step: If less than 6 V 
  6. Ignition/Vehicle & All vehicle systems OFF
  7. Test for greater than 5 kΩ between the test points: Signal circuit terminal 2 and Ground
    • If 5 kΩ or less 
    1. Disconnect the K85P Restraint Occupant Classification System Module - Passenger
    2. Test circuit 3947 for short to ground
      • If short to ground found, repair the fault on the circuit
      • Go to next step: If infinite resistance
    3. Replace the K85P Restraint Occupant Classification System Module - Passenger
    • Go to next step: If Greater than 5 kΩ 
  8. Disconnect the K85P Restraint Occupant Classification System Module - Passenger
  9. Test for less than 2 Ω between the test points: Signal circuit terminal 2 at B61P Seat Belt Tension Sensor - Passenger and The other end of the circuit at Control module harness
    • If 2 Ω or greater 

      Repair the open/high resistance in the circuit.

    • Go to next step: If less than 2 Ω 
  10. If all conditions test normal = Replace the B61P Seat Belt Tension Sensor - Passenger
  11. Operate the vehicle within the Conditions for Running the DTC
  12. Verify the DTC B1491 is not set.
    • If the DTC is set 

      Replace the K85P Restraint Occupant Classification System Module - Passenger

    • Go to next step: If the DTC is not set 
  13. A fault is not currently present and may be an intermittent condition.
About FixVault