LEMON Manuals: Even more car manuals for everyone
Home >> Acura >> 2021 >> ILX >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Supplemental Restraint System (SRS) - DTC Diagnostics (3 Of 3) (Except Hybrid) >> DTC Troubleshooting >> SRS DTC 43-1x, 45-1x

SRS DTC 43-1x, 45-1x

DTC 43-1x ("x" can be 0 thru 9 or A thru F)  : No Signal From the Left Side Impact Sensor (first)

DTC 45-1x ("x" can be 0 thru 9 or A thru F)  : No Signal From the Left Side Impact Sensor (second)

DTC Description DTC
   

DTC (SRS)

  1. DTC check

    -1. Clear the DTCs with the HDS .

    -2. Press the engine start/stop button to select the ON mode, then wait for 10 seconds.

    -3. Check for DTCs with the HDS .

    DTC Description DTC
       

    Are DTCs indicated?

    DTC 43-11 or 43-12 

    Go to step 2.

    DTC 45-11 or 45-12 

    Go to step 12.

    DTC 43-xx (except 43-1x) 

    Replace the left side impact sensor (first) , then clear the DTC.

    DTC 45-xx (except 45-1x) 

    Replace the left side impact sensor (second) , 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. Press the engine start/stop button to select the OFF mode.

    -2. Check the following connector 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. Repair the poor connector connections whichever was the cause of the problem in step 2.

    -2. Clear the DTCs with the HDS .

    -3. Press the engine start/stop button to select the ON mode, then wait for 10 seconds.

    -4. Check for DTCs with the HDS .

    DTC Description DTC
    43-11 No signal from the left side impact sensor (first)  
    43-12 No signal from the left side impact sensor (first)  

    Is 43-11 or 43-12 indicated?

    YES 

    Press the engine start/stop button to select the OFF 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. Reconnect the negative cable to the battery.

    -3. Clear the DTCs with the HDS .

    -4. Press the engine start/stop button to select the ON mode, then wait for 10 seconds.

    -5. Check for DTCs with the HDS .

    DTC Description DTC
    43-11 No signal from the left side impact sensor (first)  
    43-12 No signal from the left side impact sensor (first)  

    Is DTC 43-11 or 43-12 indicated?

    YES 

    Go to step 5.

    NO 

    Replace the left side impact sensor (first) , then clear the DTC.

  5. Shorted wire check (LS1+ line to LS1- line)

    -1. Press the engine start/stop button to select the OFF mode.

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

    -3. 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)

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

    Test condition OFF 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 circuit LS1+, LS1-
    Test point 1 Left side impact sensor (first) 4P connector No. 2 (on the floor wire harness)
    Test point 2 Left side impact sensor (first) 4P connector No. 3 (on the floor wire harness)
    GHH475495Courtesy of HONDA, U.S.A., INC.

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

    YES 

    The LS1+ and LS1- 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 (LS2+ line to LS2- line)

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

    Test condition OFF 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 circuit LS2+, LS2-
    Test point 1 Left side impact sensor (first) 4P connector No. 1 (on the floor wire harness)
    Test point 2 Left side impact sensor (first) 4P connector No. 4 (on the floor wire harness)
    GHH475496Courtesy of HONDA, U.S.A., INC.

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

    YES 

    The LS2+ and LS2- 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 (LS1+, LS1- lines)

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

    Test condition OFF 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 circuit LS1+
    Test point 1 Left side impact sensor (first) 4P connector No. 3 (on the floor wire harness)
    Test point 2 Body ground
    Test circuit LS1-
    Test point 1 Left side impact sensor (first) 4P connector No. 2 (on the floor wire harness)
    Test point 2 Body ground
    GHH475497Courtesy of HONDA, U.S.A., INC.

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

    YES 

    The LS1+ and LS1- 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 (LS2+, LS2- lines)

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

    Test condition OFF 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 circuit LS2+
    Test point 1 Left side impact sensor (first) 4P connector No. 1 (on the floor wire harness)
    Test point 2 Body ground
    Test circuit LS2-
    Test point 1 Left side impact sensor (first) 4P connector No. 4 (on the floor wire harness)
    Test point 2 Body ground
    GHH475498Courtesy of HONDA, U.S.A., INC.

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

    YES 

    The LS2+ and LS2- 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 (LS1+, LS1- lines to power)

    -1. Reconnect the negative cable to the battery.

    -2. Press the engine start/stop button to select the ON mode.

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

    Test condition 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 circuit LS1+
    Test point 1 Left side impact sensor (first) 4P connector No. 3 (on the floor wire harness)
    Test point 2 Body ground
    Test circuit LS1-
    Test point 1 Left side impact sensor (first) 4P connector No. 2 (on the floor wire harness)
    Test point 2 Body ground
    GHH475499Courtesy of HONDA, U.S.A., INC.

    Is there 0.2 V or less?

    YES 

    The LS1+ and LS1- 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 (LS2+, LS2- lines to power)

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

    Test condition 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 circuit LS2+
    Test point 1 Left side impact sensor (first) 4P connector No. 1 (on the floor wire harness)
    Test point 2 Body ground
    Test circuit LS2-
    Test point 1 Left side impact sensor (first) 4P connector No. 4 (on the floor wire harness)
    Test point 2 Body ground
    GHH475500Courtesy of HONDA, U.S.A., INC.

    Is there 0.2 V or less?

    YES 

    The LS2+ and LS2- 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 (LS1+, LS1- lines)

    -1. Press the engine start/stop button to select the OFF mode.

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

    Terminal A SRS unit connector B (39P) No. 28
    Terminal B SRS unit connector B (39P) No. 29
    GHH475501Courtesy of HONDA, U.S.A., INC.

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

    Test condition OFF 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. 28 and No. 29: jumped
    Test circuit LS1+, LS1-
    Test point 1 Left side impact sensor (first) 4P connector No. 2 (on the floor wire harness)
    Test point 2 Left side impact sensor (first) 4P connector No. 3 (on the floor wire harness)
    GHH475502Courtesy of HONDA, U.S.A., INC.

    Is there 1.0 Ω or less?

    YES 

    The LS1+ and LS1- wires are OK. Disconnect and reconnect the connector, and then check the DTC again. If the DTC is still present, replace the SRS unit .

    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. Press the engine start/stop button to select the OFF mode.

    -2. Check the following connector 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. Repair the poor connector connections whichever was the cause of the problem in step 12.

    -2. Clear the DTCs with the HDS .

    -3. Press the engine start/stop button to select the ON mode, then wait for 10 seconds.

    -4. Check for DTCs with the HDS .

    DTC Description DTC
    45-11 No signal from the left side impact sensor (second)  
    45-12 No signal from the left side impact sensor (second)  

    Is DTC 45-11 or 45-12 indicated?

    YES 

    Press the engine start/stop button to select the OFF mode, then go to step 14.

    NO 

    The system is OK at this time.

  14. Open wire check (LS2+, LS2- 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 No. 1 (on the floor wire harness)
    Terminal B Left side impact sensor (first) 4P connector No. 4 (on the floor wire harness)
    GHH475503Courtesy of HONDA, U.S.A., INC.

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

    Test condition OFF 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 circuit LS2+, LS2-
    Test point 1 Left side impact sensor (second) 2P connector No. 1 (on the floor wire harness)
    Test point 2 Left side impact sensor (second) 2P connector No. 2 (on the floor wire harness)
    GHH475504Courtesy of HONDA, U.S.A., INC.

    Is there 1.0 Ω or less?

    YES 

    The LS2+ and LS2- wires are OK. Replace the left side impact sensor (second) , 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.