Test Notes

Normal Operation
The air bag diagnostic monitor measures the resistance between Pin C2-20, Circuit 620 (P/LB) and the reference ground at Pin C1-18, Circuit 570 (BK/W). If the air bag diagnostic monitor measures a difference of more than 3.0 ohms between the ground at Pin C1-18, Circuit 570 (BK/W) and the ground at Pin C2-20, 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 C1-18 and C2-20, 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 C2-20, 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 C2-10 and C1-18 of the air bag diagnostic monitor in Circuit 570 (BK/W).