Test H: LFC 21/DTC 51921 - ECS Bracket High Resistance/Incorrect Mounting

H1 - H2:

H3 - H4:

H5 - H6:

Normal Operation
The air bag Electronic Crash Sensor (ECS) module monitors the resistance between the ground connector 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 Diagnostic Trouble Code (DTC) B1921 in memory and flash Lamp Fault Code (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.