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This is for the left hand primary crash sensor. This code sets if return circuit from the sensor is open or shorted to power.
Here is the description:
Pinpoint Test L: LFC 42/DTC B1942 - LH Air Bag Sensor Feed/Return Circuit Open
The voltage at Pin C232-15, Circuit 619 (PK/W), is set by the air bag diagnostic monitor to be slightly less than battery voltage. Circuit 619 (PK/W) is connected to Circuit 625 (Y/LG) inside the LH air bag sensor. Therefore, the voltage at Pin C233-23, Circuit 625 (Y/LG) should be the same as the voltage at Pin C232-15, Circuit 619 (PK/W).
The air bag diagnostic monitor periodically pulls the voltage at Pin C232-15, Circuit 619 (PK/W), low to verify the connection to Pin C233-23, Circuit 625 (Y/LG). If the voltage at Pin C233-23, Circuit 625 (Y/LG), does not pull low as a result of this test, the air bag diagnostic monitor will store in memory the diagnostic trouble code (DTC) B1942 and flash a lamp fault code (LFC) 42 on the air bag indicator. If the connection between Pin C232-15, Circuit 625 (Y/LG), and Pin C233-23, Circuit 625 (Y/LG), is later repaired, the DTC B1942 will be stored in memory.
Failure to get low voltage at Pin C233-23, Circuit 625 (Y/LG), during the test can be caused by:
Here is the wiring schematic of the sensor:
This is the crash sensor located at the left front of the engine compartment next ro the drivers headlamp. It also goes thru another connector C146 which is located at the left rear of the engine compartment.See top left of this pic.
Here is a list of the possible causes:
Here is the schematic for the right sensor for circuits 617 and 624 if you need to check them for short to power also.