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)

WARNING: This page is about a different car, the 2013 Acura MDX, 2012 Acura MDX, 2011 Acura MDX, and 2010 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Before doing this troubleshooting procedure, find out if the vehicle was in a collision. If so, verify that all the required components were replaced with new components, of the correct part number, and that they were properly installed (see COMPONENT REPLACEMENT/INSPECTION AFTER DEPLOYMENT ).
Before doing this troubleshooting procedure, review SRS PRECAUTIONS AND PROCEDURES , GENERAL TROUBLESHOOTING INFORMATION , and Battery Terminal Disconnection and Reconnection (see USING THE GR8 BATTERY DIAGNOSTIC STATION ).
Before replacing the SRS unit, check the SRS unit software version with the HDS. If the software version is not the latest, update the SRS unit software (see SRS UNIT UPDATE ), and retest.

Clear the DTCs with the HDS (see HOW TO CLEAR DTCS ).
Turn the ignition switch to ON (II), then wait for 10 seconds.
Check for DTCs with the HDS (see HOW TO CLEAR DTCS ).
Is DTC 45-1x (except 45-11) indicated?

YES -Faulty left side impact sensor (second); replace the left side impact sensor (second) (see SIDE IMPACT SENSOR (SECOND) REPLACEMENT ), then clear the DTC.

NO -Go to step 4.
Clear the DTCs with the HDS (see HOW TO CLEAR DTCS ).
Turn the ignition switch to ON (II), then wait for 10 seconds.
Check for DTCs with the HDS (see HOW TO CLEAR DTCS ).
Is DTC 43-1x (except 43-11) indicated?

YES -Faulty left side impact sensor (first); replace the left side impact sensor (first), then clear the DTC.

NO -Go to step 7.
Clear the DTCs with the HDS (see HOW TO CLEAR DTCS ).
Turn the ignition switch to ON (II), then wait for 10 seconds.
Check for DTCs with the HDS (see HOW TO CLEAR DTCS ).
Is DTC 45-11 indicated?

YES -Go to step 13.

NO -Go to step 10.
Clear the DTCs with the HDS (see HOW TO CLEAR DTCS ).
Turn the ignition switch to ON (II), then wait for 10 seconds.
Check for DTCs with the HDS (see HOW TO CLEAR DTCS ).
Is DTC 43-11 indicated?

YES -Go to step 42.

NO -Intermittent failure, the system is OK at this time. Go to TROUBLESHOOTING INTERMITTENT FAILURES . If another DTC is indicated, troubleshoot the DTC.
Turn the ignition switch to LOCK (0).
Check the connections between SRS unit connector B (39P) and the SRS unit, and between the floor wire harness 4P connector and the left side impact sensor (first) (see SIDE IMPACT SENSOR (FIRST) REPLACEMENT ) and between the floor wire 2P connector and left side impact sensor (second) (see SIDE IMPACT SENSOR (SECOND) REPLACEMENT ).
Are the connections OK?

YES -Go to step 15.

NO -Replace the floor wire harness, then clear the DTC.
Substitute a known-good side impact sensor.
Exchange the left side impact sensor (second) for the impact sensor prepared in step 15.
Reconnect the negative cable to the battery.
Clear the DTCs with the HDS (see HOW TO CLEAR DTCS ).
Turn the ignition switch to ON (II), then wait for 10 seconds.
Check for DTCs with the HDS (see HOW TO CLEAR DTCS ).
Is DTC 45-11 indicated?

YES -Go to step 21.

NO -Faulty left side impact sensor (second); replace the left side impact sensor (second) (see SIDE IMPACT SENSOR (SECOND) REPLACEMENT ), then clear the DTC.
Turn the ignition switch to LOCK (0).
Disconnect the negative cable from the battery, then wait at least 3 minutes.
Return the impact sensor which was replaced in step 16.
Substitute a known-good side impact sensor.
Exchange the left side impact sensor (first) for the impact sensor prepared in step 24.
Reconnect the negative cable to the battery.
Clear the DTCs with the HDS (see HOW TO CLEAR DTCS ).
Turn the ignition switch to ON (II), then wait for 10 seconds.
Check for DTCs with the HDS (see HOW TO CLEAR DTCS ).
Is DTC 45-11 indicated?

YES -Go to step 30.

NO -Faulty left side impact sensor (first); replace the left side impact sensor (first) (see SIDE IMPACT SENSOR (FIRST) REPLACEMENT ), then clear the DTC.
Turn the ignition switch to LOCK (0).
Disconnect the negative cable from the battery, then wait at least 3 minutes.
Disconnect SRS unit connector B (39P) from the SRS unit (see DISCONNECTING SYSTEM CONNECTORS ).
Disconnect the floor wire harness 4P connector from the left side impact sensor (first) (see SIDE IMPACT SENSOR (FIRST) REPLACEMENT ).
Disconnect the floor wire harness 2P connector from the left side impact sensor (second) (see SIDE IMPACT SENSOR (SECOND) REPLACEMENT ).
Measure the resistance between floor wire harness 2P connector (left side impact sensor (second)) terminals No. 1 and No. 2.

Fig 1: Measuring Resistance Between Floor Wire Harness 2P Connector Terminals No. 1 And No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there an open circuit or at least 1 MΩ?

YES -Go to step 36.

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.
Measure the resistance between body ground and floor wire harness 2P connector (left side impact sensor (second)) terminals No. 1 and No. 2 individually.

Fig 2: Measuring Resistance Between Body Ground And Floor Wire Harness 2P Connector Terminals No. 1 And No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there an open circuit or at least 1 MΩ?

YES -Go to step 37.

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.
Reconnect the negative cable to the battery.
Turn the ignition switch to ON (II), then wait for 10 seconds.
Measure the voltage between body ground and floor wire harness 2P connector (left side impact sensor (second)) terminals No. 1 and No. 2 individually.

Fig 3: Measuring Voltage Between Body Ground And Floor Wire Harness 2P Connector Terminals No. 1 And No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there less than 0.2 V?

YES -Go to step 40.

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.
Turn the ignition switch to LOCK (0).
Measure the resistance between floor wire harness 4P connector (left side impact sensor (first)) terminals No. 1 and No. 4 and floor wire harness 2P connector (left side impact sensor (second)) terminals No. 1 and No. 2.

Fig 4: Measuring Resistance Between Floor Wire Harness 4P Connector Terminals No. 1 And No. 4 And Floor Wire Harness 2P Connector Terminals No. 1 And No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there less than 1.0 Ω?

YES -Disconnect and reconnect the connector, and then check DTC again. If the problem is still present, replace the SRS unit (see SRS UNIT REPLACEMENT ).

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.
Turn the ignition switch to LOCK (0).
Check the connections between SRS unit connector B (39P) and the SRS unit, and between the floor wire harness 4P connector and the left side impact sensor (first) (see SIDE IMPACT SENSOR (FIRST) REPLACEMENT ) and between the floor wire harness 2P connector and left side impact sensor (second) (see SIDE IMPACT SENSOR (SECOND) REPLACEMENT ).
Are the connections OK?

YES -Go to step 44.

NO -Replace the floor wire harness, then clear the DTC.
Substitute a known-good side impact sensor.
Exchange the left side impact sensor (first) for the impact sensor prepared in step 44.
Reconnect the negative cable to the battery.
Clear the DTCs with the HDS (see HOW TO CLEAR DTCS ).
Turn the ignition switch to ON (II), then wait for 10 seconds.
Check for DTCs with the HDS (see HOW TO CLEAR DTCS ).
Is DTC 43-11 indicated?

YES -Go to step 50.

NO -Faulty left side impact sensor (first); replace the left side impact sensor (first) (see SIDE IMPACT SENSOR (FIRST) REPLACEMENT ), then clear the DTC.
Turn the ignition switch to LOCK (0).
Disconnect the negative cable from the battery, then wait at least 3 minutes.
Disconnect SRS unit connector B (39P) from the SRS unit (see DISCONNECTING SYSTEM CONNECTORS ).
Disconnect the floor wire harness 4P connector from the left side impact sensor (first).
Measure the resistance between floor wire harness 4P connector (left side impact sensor (first)) terminals No. 2 and No. 3.

Fig 5: Measuring Resistance Between Floor Wire Harness 4P Connector Terminals No. 2 And No. 3
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there an open circuit or at least 1 MΩ?

YES -Go to step 55.

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.
Measure the resistance between body ground and floor wire harness 4P connector (left side impact sensor (first)) terminals No. 2 and No. 3 individually.

Fig 6: Measuring Resistance Between Body Ground And Floor Wire Harness 4P Connector Terminals No. 2 And No. 3
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there an open circuit or at least 1 MΩ?

YES -Go to step 56.

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.
Reconnect the negative cable to the battery.
Turn the ignition switch to ON (II).
Measure the voltage between body ground and floor wire harness 4P connector (left side impact sensor (first)) terminals No. 2 and No. 3 individually.

Fig 7: Measuring Voltage Between Body Ground And Floor Wire Harness 4P Connector Terminals No. 2 And No. 3
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there less than 0.2 V?

YES -Go to step 59.

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.
Turn the ignition switch to LOCK (0).
Measure the resistance between floor wire harness 4P connector (left side impact sensor (first)) terminals No. 2 and No. 3 and SRS unit connector B (39P) terminals No. 36 and No. 37.

Fig 8: Measuring Resistance Between Floor Wire Harness 4P Connector Terminals No. 2 And No. 3 And SRS Unit Connector B (39P) Terminals No. 36 And No. 37
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there less than 1.0 Ω?

YES -Disconnect and reconnect the connector, and then check DTC again. If the problem is still present, replace the SRS unit (see SRS UNIT REPLACEMENT ).

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.