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 approximately 10 volts (+/- 1 volt). The resistance to ground on these pins in the diagnostic monitor harness connector should be infinite. The resistance across the normally open contacts of the two primary crash 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 LH or RH radiator support primary sensor contacts, it will cause the diagnostic voltage on these pins to drop below normal levels. If the air bag diagnostic monitor measures that this voltage has dropped to between 5 and 10 volts, the air bag diagnostic monitor senses it has an internal voltage regulation failure and will flash code 53. Note that a direct short to ground in the LH or RH radiator support primary sensor circuits will drop the voltage to less than 5 volts and the air bag diagnostic monitor will flash code 14 on the air bag indicator.

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

Possible Causes
A voltage drop in the front air bag sensors circuits or an internal air bag diagnostic monitor failure can be caused by:

1. A partial drop in voltage in the primary sensor circuits due to resistance to ground on the primary sensor wiring or any resistance across the normally open primary sensor contacts.
2. Internal air bag diagnostic monitor self-test failure.