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Home >> Acura >> 2017 >> TLX Base, 2.4L Eng >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Supplemental Restraint System SRS - Diagnostics (B0028-12 - U3000-51) >> DTC Troubleshooting >> DTC B0090-87: No Signal From the Left Front Impact Sensor (2015-17)

DTC B0090-87: No Signal From the Left Front Impact Sensor (2015-17)

Special Tools Required: 

SRS Inflator Simulator 07SAZ-TB4011A 

SRS Simulator Lead L 070AZ-SNAA300 

NOTE: 

Before doing this troubleshooting procedure: 

DTC Description DTC
B0090-87 No signal from the left front impact sensor  

DTC (SRS)

  1. Problem verification

    -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
    B0090-87 No signal from the left front impact sensor  

    Is DTC B0090-87 indicated?

    YES 

    The failure is duplicated. Go to step 2.

    NO 

    Intermittent failure, the system is OK at this time. Go to Troubleshooting Intermittent Failures - Refer to: How to Troubleshoot the SRS . 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 connector connections.

    SRS unit connector A (39P)
    Left front impact sensor 2P connector (on the engine compartment wire harness)
    Connector between the SRS unit and the left front impact sensor

    Are the connectors OK?

    YES 

    Go to step 4.

    NO 

    Go to step 3.

  3. System check

    -1. Repair the loose connector connections whichever was the cause of 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
    B0090-87 No signal from the left front impact sensor  

    Is DTC B0090-87 indicated?

    YES 

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

    NO 

    The system is OK at this time.

  4. Shorted wire check (LFS+ line to LFS- line)

    -1. Disconnect the negative cable from the 12 volt battery, then wait at least 3 minutes.

    - 2. Disconnect the following connectors.

    SRS unit connector A (39P)
    Left front impact sensor 2P connector (on the engine compartment wire harness)

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

    Test condition Vehicle OFF (LOCK) mode
    SRS unit connector A (39P): disconnected
    Left front impact sensor 2P connector (on the engine compartment wire harness): disconnected
    Test point 1 SRS unit connector A (39P) No. 28 - Refer to: SRS Unit Connector for Inputs and Outputs
    Test point 2 SRS unit connector A (39P) No. 29 - Refer to: SRS Unit Connector for Inputs and Outputs

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

    YES 

    The LFS+ and LFS- wires are not shorted. Go to step 5.

    NO 

    Short to another wire in the engine compartment wire harness or the dashboard wire harness; replace the faulty harness, then clear the DTC.

  5. Shorted wire check (LFS+, LFS- lines)

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

    Test condition Vehicle OFF (LOCK) mode
    SRS unit connector A (39P): disconnected
    Left front impact sensor 2P connector (on the engine compartment wire harness): disconnected
    Test point 1 SRS unit connector A (39P) No. 28 - Refer to: SRS Unit Connector for Inputs and Outputs
    Test point 2 Body ground
    Test point 1 SRS unit connector A (39P) No. 29 - Refer to: SRS Unit Connector for Inputs and Outputs
    Test point 2 Body ground

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

    YES 

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

    NO 

    Short to ground in the engine compartment wire harness or the dashboard wire harness; replace the faulty harness, then clear the DTC.

  6. Shorted wire check (LFS+, LFS- lines to power)

    -1. Reconnect the negative cable to the 12 volt 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 A (39P): disconnected
    Left front impact sensor 2P connector (on the engine compartment wire harness): disconnected
    Test point 1 SRS unit connector A (39P) No. 28 - Refer to: SRS Unit Connector for Inputs and Outputs
    Test point 2 Body ground
    Test point 1 SRS unit connector A (39P) No. 29 - Refer to: SRS Unit Connector for Inputs and Outputs
    Test point 2 Body ground

    Is there 0.2 V or less?

    YES 

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

    NO 

    Short to power in the engine compartment wire harness or the dashboard wire harness; replace the faulty harness, then clear the DTC.

  7. Open wire check (LFS+, LFS- lines)

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

    - 2. Connect the black terminal (A) of SRS simulator lead L to the SRS inflator simulator (jumper connector), then connect SRS simulator lead L to the left front impact sensor 2P connector (B) on the engine compartment wire harness.

    GHH204499Courtesy of HONDA, U.S.A., INC.

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

    Test condition Vehicle OFF (LOCK) mode
    SRS unit connector A (39P): disconnected
    Left front impact sensor 2P connector (on the engine compartment wire harness): disconnected
    Left front impact sensor 2P connector (on the engine compartment wire harness): connected to SRS simulator lead L
    Test point 1 SRS unit connector A (39P) No. 28 - Refer to: SRS Unit Connector for Inputs and Outputs
    Test point 2 SRS unit connector A (39P) No. 29 - Refer to: SRS Unit Connector for Inputs and Outputs

    Is there 1.0 Ω or less?

    YES 

    The LFS+ and LFS- wires are OK. Replace the left front impact sensor , then clear the DTC, and retest. If the DTC is still present, replace the SRS unit - Refer to: SRS Unit Removal and Installation .

    NO 

    Open in the engine compartment wire harness or the dashboard wire harness; replace the faulty harness, then clear the DTC.