Test Notes

NORMAL OPERATION
The air bag diagnostic monitor measures the resistance between Pin C276-20, Circuit 620 (P/LB) and the reference ground at Pin C277-18, Circuit 57 (BK). if the air bag diagnostic monitor measures a difference of more than 3.0 ohms between the ground at Pin C277-18, Circuit 57 (BK) and the ground at Pin C276-20, Circuit 620 (P/LB), the air bag diagnostic monitor will store in memory and flash lamp fault code 45 on the AIR BAG indicator. Should the difference in resistance between Pin C277-18 and C276-20, Circuit 620 (P/LB) be serviced or otherwise reduced to less than 3.0 ohms, the air bag diagnostic monitor will store DTC B1945 in memory.

NOTE: Circuit 620 (P/LB) is riveted to the side of the LH primary crash sensor case and the case of the sensor is grounded to the vehicle at its mounting point.

POSSIBLE CAUSES
A high resistance reading on Pin C276-20, Circuit 620 (P/LB) to ground can be caused by:
- a poor attachment of LH primary crash front air bag sensor and bracket due to loose mounting, dirt or corrosion at its mounting location.
- an open or damaged wire in Circuit 620 (P/LB).
- an open wire or loose rivet inside LH primary crash front air bag sensor and bracket.
- a poor reference ground at Pins C276-10 and C277-18 of the air bag diagnostic monitor in Circuit 57 (BK).