DTC 84

Test AK: DTC 84 Passenger Reserve Diode Shorted:

Supplemental Inflatable Restraint (SIR):

OPERATION:
During the "Turn-ON" tests, performed at the beginning of each ignition cycle, the DERM delays charging of the "Driver 36 VLR" and "Passenger 36 VLR" power supplies. While the delay is active the DERM measures the voltage at the "Driver 36 VLR" terminal "A4", "Passenger 36 VLR" terminal "A3", "Driver Source Sense" terminal "A5", and "Passenger Source Sense" terminal "A6." When the Passenger Reserve Diode is shorted, "Ignition 1" voltage is measured at "Passenger 36 VLR" from the Forward Biased Passenger Ignition Diode. When the voltage measured at "Passenger 36 VLR" is within a specified range of "Ignition 1" voltage for eight consecutive "Turn-ON" tests. History DTC 84 is set.

Test Conditions: Tested once each ignition cycle during the "Turn-ON" tests while the "36 VLR Delay" is active.

Failure Conditions: History DTC 64 is set when the voltage measured at "Passenger 36 VLR" terminal "A3" is within a specified range of "Ignition 1" voltage for eight consecutive "Turn-ON" tests and no "higher priority faults" are detected.

Action Taken: DERM sets a History Diagnostic Trouble Code.

Conditions to Clear: History DTC 84 will clear when the voltage measured at "Passenger 36 VLR" terminal "A3" indicates that the power supply is in a discharged state during "Turn-ON" tests.

POSSIBLE CAUSES:
Test Description: Number(S) below refer to circled number(S) on the diagnostic chart.
1. This test determines if the malfunction is due to a shorted Passenger Reserve Diode within the Dual Pole Arming Sensor.

DIAGNOSTIC AIDS:
This diagnostic trouble code will not set as a current DTC. Therefore follow the DTC chart to diagnose a history DTC 84.