Test Notes

Normal Operation
The normal voltage on pins 2, 6, 17 and 18 is controlled by an internal resistor inside the air bag diagnostic monitor and is internally regulated to 10 (+/-one) volts. The resistance between these pins in the air bag diagnostic monitor connector and ground should be infinite. The resistance across the normally open contacts of the two radiator primary crash front air bag sensors should also be infinite. The air bag diagnostic monitor measures the voltage on pins 2, 6, 17 and 18. If there is any resistance to ground on any of these pins or across the radiator primary crash front air bag sensor contacts, it will cause the diagnostic voltage on these pins to drop below normal levels. If the air bag diagnostic monitor measures a voltage drop to between 5 and 10 volts, the air bag diagnostic monitor senses an internal voltage regulation failure and will flash Diagnostic Trouble Code (DTC) 53. Note that a direct short to ground in the radiator primary crash front air bag sensor circuits will drop the voltage to less than 5 volts, and the air bag diagnostic monitor will flash DTC 14 on the air bag warning indicator.

The air bag diagnostic monitor also performs several on-board diagnostics every time the ignition switch is turned to ON. If any of these tests fail, the air bag diagnostic monitor will flash DTC 53 on the air bag warning indicator.

Possible Causes
A voltage drop in the radiator primary crash front air bag sensor circuits or an internal air bag diagnostic monitor failure can be caused by:
- A partial drop in voltage in the radiator primary crash front air bag sensor circuits due to resistance to ground on the front air bag sensor wiring or any resistance across the normally open radiator primary crash front air bag sensor contacts.
- Internal air bag diagnostic monitor on-board diagnostic failure.