Originally Posted by HomerWinzlow

You could also be mistaking a code 42 for a code 24

LFC 42/DTC B1942 — LH Air Bag Sensor Feed/Return Circuit Open

Normal Operation

The voltage at Pin C209-15, 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 C208-23, Circuit 625 (Y/LG) should be the same as the voltage at Pin C209-15, Circuit 619 (PK/W).

The air bag diagnostic monitor periodically pulls the voltage at Pin C209-15, Circuit 619 (PK/W), low to verify the connection to Pin C208-23, Circuit 625 (Y/LG). If the voltage at Pin C208-23, 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 C209-15, Circuit 625 (Y/LG), and Pin C208-23, Circuit 625 (Y/LG), is later repaired, the DTC B1942 will be stored in memory.

Possible Causes

Failure to get low voltage at Pin C208-23, Circuit 625 (Y/LG), during the test can be caused by:

an open circuit in the wiring harness in either Circuit 619 (PK/W) or Circuit 625 (Y/LG).
an open circuit inside the LH air bag sensor across Circuit 619 (PK/W) or Circuit 625 (Y/LG).
a short to battery or ignition voltage in any of the Circuits 617 (PK/O), 619 (PK/W), 624 (Y/W), or 625 (Y/LG).