21: Safing Sensor Not Mounted to Vehicle Properly
DIAGNOSTIC TROUBLE CODE 21 - DIAGNOSTIC MONITOR NOT MOUNTED TO VEHICLE PROPERLYNormal Operation
The air bag diagnostic monitor measures the resistance between the ground connection at its bracket and the reference ground at Pin C1-15. If the air bag diagnostic monitor measures a difference of more than 3.0 ohms between the ground at Pin C1-15 and the ground at its bracket, the air bag diagnostic monitor will store in memory and flash a DTC 21 on the AIR BAG indicator. Should the difference in resistance between Pins C1-18 and air bag diagnostic monitor bracket ground be serviced or otherwise reduced to less than 3.0 ohms, the air bag diagnostic monitor will store a DTC 61 in memory.
Possible Causes
A high resistance reading at the air bag diagnostic monitor bracket ground can be caused by:
- A poor attachment of the air bag diagnostic monitor due to loose mounting, dirt, or corrosion at the air bag diagnostic monitor bracket mounting surface(s).
- A poor reference ground at Pins C2-10 and C1-18 of the air bag diagnostic monitor Circuit 57 (BK).
Electrical Schematic - Diagnostic Trouble Code 21:
Pinpoint Test - 21-1 - 21-4:
