Operation CHARM: Car repair manuals for everyone.

DTC 84

Z�� Diagnostic Chart:




Wiring Diagram:






CIRCUIT DESCRIPTION
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" test while the "36 VLR Delay" is active.

FAILURE CONDITIONS
History DTC 84 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.

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test determines whether the malfunction is due to a shorted passenger reserve diode within the dual pole arming sensor or a malfunctioning DERM.