H: LFC 21/DTC B1921-ECS Bracket Hi Resist/Incorrectly Mounted

Normal Operation
The air bag Electronic Crash Sensor (ECS) module monitors the resistance between the ground connection at its housing and the reference ground at Pins C200-18 and C200-21. If the ECS detects a resistance greater than 1.0 ohm, the ECS will store DTC B1921 in memory and flash LFC 21 (or higher priority code if one exists) on the air bag indicator.

Possible Causes
High resistance between the ECS module housing ground and pin ground can be caused by:
- ECS connected but not attached to the right cowl mounting surface.
- a poor attachment of the air bag ECS due to loose mounting, dirt, or corrosion at the mounting surface.
- poor reference ground at Pins C200-18 and C200-21, Circuit 875 (BK/LB) of the ECS.

Pinpoint Test Steps:

H1 - H2:

H3 - H5:

H6: