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Home >> Acura >> 2017 >> MDX Base >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Supplemental Restraint System (SRS) - Diagnostics (3 Of 3) (Except Hybrid) >> DTC Troubleshooting >> DTC B0091-87, B0092-87 (2017 2018 2019 2020)

DTC B0091-87, B0092-87 (2017 2018 2019 2020)

DTC B0091-87  : No Signal From the Left Side Impact Sensor (first)DTC B0092-87  : No Signal From the Left Side Impact Sensor (second)

DTC Description DTC
B0091-87 No signal from the left side impact sensor (first)  
B0092-87 No signal from the left side impact sensor (second)  

DTC (SRS)

  1. DTC check

    -1. Clear the DTCs with the HDS.

    - 2. Turn the vehicle to the ON mode, then wait for 10 seconds.

    - 3. Check for DTCs with the HDS.

    DTC Description DTC
    B0091-4A Internal failure of the left side impact sensor (first)  
    B0091-87 No signal from the left side impact sensor (first)  
    B0091-92 Internal failure of the left side impact sensor (first)  
    B0092-4A Internal failure of the left side impact sensor (second)  
    B0092-87 No signal from the left side impact sensor (second)  
    B0092-92 Internal failure of the left side impact sensor (second)  

    Are DTCs indicated?

    DTC B0091-87

    Go to step 2.

    DTC B0092-87

    Go to step 12.

    DTC B0091-4A or B0091-92

    Replace the left side impact sensor (first) - Refer to: Side Impact Sensor (First) Removal and Installation, or Side Impact Sensor (Second) Removal and Installation , then clear the DTC.

    DTC B0092-4A or B0092-92

    Replace the left side impact sensor (second) - Refer to: Side Impact Sensor (First) Removal and Installation, or Side Impact Sensor (Second) Removal and Installation , then clear the DTC.

    NO DTC

    Intermittent failure, the system is OK at this time. Go to Troubleshooting Intermittent Failures. If another DTC is indicated, troubleshoot the DTC.

  2. Connector connection check

    -1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Check the following connections.

    SRS unit connector B (39P)
    Left side impact sensor (first) 4P connector (on the floor wire harness)
    Left side impact sensor (second) 2P connector (on the floor wire harness)

    Are the connectors OK?

    YES 

    Go to step 4.

    NO 

    Go to step 3.

  3. System check

    -1. Reset the loose connections that caused the problem in step 2.

    - 2. Clear the DTCs with the HDS.

    - 3. Turn the vehicle to the ON mode, then wait for 10 seconds.

    - 4. Check for DTCs with the HDS.

    DTC Description DTC
    B0091-87 No signal from the left side impact sensor (first)  

    Is DTC B0091-87 indicated?

    YES 

    Turn the vehicle to the OFF (LOCK) mode, then go to step 4.

    NO 

    The system is OK at this time.

  4. Left side impact sensor (first) substituting

    -1. Substitute a known-good left side impact sensor (first).

    - 2. the negative cable to the Battery.

    - 3. Clear the DTCs with the HDS.

    - 4. Turn the vehicle to the ON mode, then wait for 10 seconds.

    - 5. Check for DTCs with the HDS.

    DTC Description DTC
    B0091-87 No signal from the left side impact sensor (first)  

    Is DTC B0091-87 indicated?

    YES 

    Go to step 5.

    NO 

    Replace the left side impact sensor (first) - Refer to: Side Impact Sensor (First) Removal and Installation, or Side Impact Sensor (Second) Removal and Installation , then clear the DTC.

  5. Shorted wire check (LBSI+ line to LBSI- line)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Disconnect the negative cable from the Battery, then wait at least 3 minutes.

    - 3. Return the left side impact sensor (first) which was replaced.

    - 4. Disconnect the following connectors.

    SRS unit connector B (39P)
    Left side impact sensor (first) 4P connector (on the floor wire harness)
    Left side impact sensor (second) 2P connector (on the floor wire harness)

    - 5. Measure the resistance between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    SRS unit connector B (39P): disconnected
    Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
    Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
    Test point 1 Left side impact sensor (first) 4P connector (female terminals) No. 2 (on the floor wire harness):
    Test point 2 Left side impact sensor (first) 4P connector (female terminals) No. 3 (on the floor wire harness):
    GHH328242Courtesy of HONDA, U.S.A., INC.

    Is there an open circuit, or at least 1 MΩ?

    YES 

    The LBSI+ and LBSI- wires are not shorted. Go to step 6.

    NO 

    Short to another wire in the floor wire harness between the SRS unit and the left side impact sensor (first); replace the floor wire harness, then clear the DTC.

  6. Shorted wire check (LCSI+ line to LCSI- line)

    -1. Measure the resistance between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    SRS unit connector B (39P): disconnected
    Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
    Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
    Test point 1 Left side impact sensor (first) 4P connector (female terminals) No. 1 (on the floor wire harness):
    Test point 2 Left side impact sensor (first) 4P connector (female terminals) No. 4 (on the floor wire harness):
    GHH328245Courtesy of HONDA, U.S.A., INC.

    Is there an open circuit, or at least 1 MΩ?

    YES 

    The LCSI+ and LCSI- wires are not shorted. Go to step 7.

    NO 

    Short to another wire in the floor wire harness between the left side impact sensor (first) and the left side impact sensor (second); replace the floor wire harness, then clear the DTC.

  7. Shorted wire check (LBSI+, LBSI- lines)

    -1. Measure the resistance between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    SRS unit connector B (39P): disconnected
    Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
    Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
    Test point 1 Left side impact sensor (first) 4P connector (female terminals) No. 2 (on the floor wire harness):
    Test point 2 Body ground
    Test point 1 Left side impact sensor (first) 4P connector (female terminals) No. 3 (on the floor wire harness):
    Test point 2 Body ground
    GHH328248Courtesy of HONDA, U.S.A., INC.

    Is there an open circuit, or at least 1 MΩ?

    YES 

    The LBSI+ and LBSI- wires are not shorted. Go to step 8.

    NO 

    Short to ground in the floor wire harness between the SRS unit and the left side impact sensor (first); replace the floor wire harness, then clear the DTC.

  8. Shorted wire check (LCSI+, LCSI- lines)

    -1. Measure the resistance between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    SRS unit connector B (39P): disconnected
    Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
    Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
    Test point 1 Left side impact sensor (first) 4P connector (female terminals) No. 1 (on the floor wire harness):
    Test point 2 Body ground
    Test point 1 Left side impact sensor (first) 4P connector (female terminals) No. 4 (on the floor wire harness):
    Test point 2 Body ground
    GHH328251Courtesy of HONDA, U.S.A., INC.

    Is there an open circuit, or at least 1 MΩ?

    YES 

    The LCSI+ and LCSI- wires are not shorted. Go to step 9.

    NO 

    Short to ground in the floor wire harness between the left side impact sensor (first) and the left side impact sensor (second); replace the floor wire harness, then clear the DTC.

  9. Shorted wire check (LBSI+, LBSI- lines to power)

    -1. the negative cable to the Battery.

    - 2. Turn the vehicle to the ON mode.

    - 3. Measure the voltage between test points 1 and 2.

    Test condition Vehicle ON mode
    SRS unit connector B (39P): disconnected
    Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
    Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
    Test point 1 Left side impact sensor (first) 4P connector (female terminals) No. 3 (on the floor wire harness):
    Test point 2 Body ground
    Test point 1 Left side impact sensor (first) 4P connector (female terminals) No. 2 (on the floor wire harness):
    Test point 2 Body ground
    GHH328254Courtesy of HONDA, U.S.A., INC.

    Is there 0.2 V or less?

    YES 

    The LBSI+ and LBSI- wires are not shorted to power. Go to step 10.

    NO 

    Short to power in the floor wire harness between the SRS unit and the left side impact sensor (first); replace the floor wire harness, then clear the DTC.

  10. Shorted wire check (LCSI+, LCSI- lines to power)

    -1. Measure the voltage between test points 1 and 2.

    Test condition Vehicle ON mode
    SRS unit connector B (39P): disconnected
    Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
    Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
    Test point 1 Left side impact sensor (first) 4P connector (female terminals) No. 1 (on the floor wire harness):
    Test point 2 Body ground
    Test point 1 Left side impact sensor (first) 4P connector (female terminals) No. 4 (on the floor wire harness):
    Test point 2 Body ground
    GHH328257Courtesy of HONDA, U.S.A., INC.

    Is there 0.2 V or less?

    YES 

    The LCSI+ and LCSI- wires are not shorted to power. Go to step 11.

    NO 

    Short to power in the floor wire harness between the left side impact sensor (first) and the left side impact sensor (second); replace the floor wire harness, then clear the DTC.

  11. Open wire check (LBSI+, LBSI- lines)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Connect terminals A and B with a jumper wire.

    Terminal A SRS unit connector B (39P) No. 38 - Refer to: SRS Unit Connector for Inputs and Outputs (2017 2018 2019 2020)
    Terminal B SRS unit connector B (39P) No. 39 - Refer to: SRS Unit Connector for Inputs and Outputs (2014 2015), or SRS Unit Connector for Inputs and Outputs (2016), or SRS Unit Connector for Inputs and Outputs (2017 2018 2019 2020)

    - 3. Measure the resistance between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    SRS unit connector B (39P): disconnected
    Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
    Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
    SRS unit connector B (39P) terminals No. 38 and No. 39: jumped
    Test point 1 Left side impact sensor (first) 4P connector (female terminals) No. 2 (on the floor wire harness):
    Test point 2 Left side impact sensor (first) 4P connector (female terminals) No. 3 (on the floor wire harness):
    GHH328260Courtesy of HONDA, U.S.A., INC.

    Is there 1.0 Ω or less?

    YES 

    The LBSI+ and LBSI- wires are OK. Disconnect and reconnect the connector, and then check the DTC again. If the DTC is still present, check for any authorized service information related to the DTCs or symptoms you are troubleshooting or replace the SRS unit - Refer to: SRS Unit Removal and Installation, or SRS Unit Removal and Installation (2017 2018 2019 2020) .

    NO 

    Open in the floor wire harness between the SRS unit and the left side impact sensor (first); replace the floor wire harness, then clear the DTC.

  12. Connector connection check

    -1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Check the following connections.

    SRS unit connector B (39P)
    Left side impact sensor (first) 4P connector (on the floor wire harness)
    Left side impact sensor (second) 2P connector (on the floor wire harness)

    Are the connectors OK?

    YES 

    Go to step 14.

    NO 

    Go to step 13.

  13. System check

    -1. Reset the loose connections that caused the problem in step 12.

    - 2. Clear the DTCs with the HDS.

    - 3. Turn the vehicle to the ON mode, then wait for 10 seconds.

    - 4. Check for DTCs with the HDS.

    DTC Description DTC
    B0092-87 No signal from the left side impact sensor (second)  

    Is DTC B0092-87 indicated?

    YES 

    Turn the vehicle to the OFF (LOCK) mode, then go to step 14.

    NO 

    The system is OK at this time.

  14. Open wire check (LCSI+, LCSI- lines)

    -1. Disconnect the negative cable from the Battery, then wait at least 3 minutes.

    - 2. Disconnect the following connectors.

    Left side impact sensor (first) 4P connector (on the floor wire harness)
    Left side impact sensor (second) 2P connector (on the floor wire harness)

    - 3. Connect terminals A and B with a jumper wire.

    Terminal A Left side impact sensor (first) 4P connector (female terminals) No. 1 (on the floor wire harness):
    Terminal B Left side impact sensor (first) 4P connector (female terminals) No. 4 (on the floor wire harness):
    GHH328263Courtesy of HONDA, U.S.A., INC.

    - 4. Measure the resistance between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
    Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
    Left side impact sensor (first) 4P connector terminals No. 1 and No. 4 (on the floor wire harness): jumped
    Test point 1 Left side impact sensor (second) 2P connector (female terminals) No. 1 (on the floor wire harness):
    Test point 2 Left side impact sensor (second) 2P connector (female terminals) No. 2 (on the floor wire harness):
    GHH328266Courtesy of HONDA, U.S.A., INC.

    Is there 1.0 Ω or less?

    YES 

    The LCSI+ and LCSI- wires are OK. Replace the left side impact sensor (second) - Refer to: Side Impact Sensor (First) Removal and Installation, or Side Impact Sensor (Second) Removal and Installation , then clear the DTC.

    NO 

    Open in the floor wire harness between the left side impact sensor (first) and the left side impact sensor (second); replace the floor wire harness, then clear the DTC.