DTC 42-1x ("x" can be 0 thru 9 or A thru F): No Signal From the Right Front Impact Sensor

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.

Special Tools Required

SRS Inflator Simulator 07SAZ-TB4011A
SRS Simulator Lead L 070AZ-SNAA300

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 42-1x indicated?

YES -Go to step 4.

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).
Disconnect the negative cable from the battery, then wait at least 3 minutes.
Check the connections between SRS unit connector A (39P) and the SRS unit, between the right engine compartment wire harness 2P connector and the right front impact sensor (see FRONT IMPACT SENSOR REPLACEMENT ).
Are the connections OK?

YES -Go to step 7.

NO -Repair the poor connections, then clear the DTC, and retest.
Disconnect SRS unit connector A (39P) from the SRS unit.
Disconnect the right engine compartment wire harness 2P connector from the right front impact sensor.
Measure the resistance between SRS unit connector A (39P) terminals No. 38 and No. 39.

Fig 1: Measuring Resistance Between SRS Unit Connector 39P Terminals No. 38 And No. 39
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there an open circuit or at least 1 MΩ?

YES -Go to step 10.

NO -Short to another wire in the right engine compartment wire harness or the dashboard wire harness; replace the faulty harness, then clear the DTC.
Measure the resistance between body ground and SRS unit connector A (39P) terminals No. 38 and No. 39 individually.

Fig 2: Measuring Resistance Between Body Ground And SRS Unit Connector 39P Terminals No. 38 And No. 39 Individually
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there an open circuit or at least 1 MΩ?

YES -Go to step 11.

NO -Short to ground in the dashboard wire harness or the right engine compartment wire harness; replace the faulty 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 SRS unit connector A (39P) terminals No. 38 and No. 39 individually.

Fig 3: Measuring Voltage Between Body Ground And SRS Unit Connector 39P Terminals No. 38 And No. 39
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there less than 0.2 V?

YES -Go to step 14.

NO -Short to power in the right engine compartment wire harness or the dashboard wire harness; replace the faulty harness, then clear the DTC.
Turn the ignition switch to LOCK (0).
Connect the SRS inflator simulator (jumper connector) and the black SRS simulator lead (A) of simulator lead L to the right engine compartment wire harness 2P connector (B).

Fig 4: Identifying Black SRS Simulator Lead And Engine Compartment Wire Harness 2P Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Measure the resistance between SRS unit connector A (39P) terminals No. 38 and No. 39.

Fig 5: Measuring Resistance Between SRS Unit Connector 39P Terminals No. 38 And No. 39
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there less than 1.0 Ω?

YES -Faulty right front impact sensor or SRS unit; replace the right front impact sensor (see FRONT IMPACT SENSOR REPLACEMENT ), then clear the DTC. If the problem is still present, replace the SRS unit (see SRS UNIT REPLACEMENT ).

NO -Open in the right engine compartment wire harness or the dashboard wire harness; replace the faulty harness, then clear the DTC.