B421 BCM Output Driver #2 Failure

The BCM has the ability of both commanding an output and checking that the commanded state has been achieved. If the commanded and the actual are not the same a code will be set.

Notes on trouble trees
1. It would be normal for code B421 to set if there was an ABS fault (code B480 or B481), therefore, diagnose the ABS codes if set.
2. This checks for proper chime control.
3. This checks for proper RAP control.

Note on Intermittents
If this code is setting intermittently along with code B48O or B481 then the ABS system should be diagnosed. If no other codes are set, symptoms of no RAP or chime operation may direct area to diagnose.