R084

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The DERM checks the Dual Pole Arming Sensor for a shorted passenger reserve diode once each ignition cycle during 'Turn-On tests. The DERM delays charging of the 'PASSENGER'S 36 VLR' power supply. While the delay is active, the DERM measures voltage at the 'PASSENGER'S 36 VLR' terminal 'A3'. When the Passenger's Diode is shorted, voltage is measured at 'PASSENGER'S 36 VLR' terminal 'A3' and the DERM increments an internal counter. If the DERM detects a shorted passenger reserve diode for eight consecutive ignition cycles, the counter stops incrementing and sets a History Code R084. The DERM resets the counter to zero when Code RO84 is cleared through On-Board diagnostics. If the failure conditions are not met, the counter remains unchanged.

TEST CONDITION(S)

1. Turn-On tests active.

2. '36 VLR Delay' active.

FAILURE CONDITION(S)

1. 'PASSENGER'S 36 VLR' terminal 'A3' voltage is greater than (Ignition 1 - 2 volts) and less than (Ignition 1+2 volts) increment counter.

2. Counter reaches 8, set History Code R084.

ACTION TAKEN

Since this code sets as History R084, it can be cleared using the 'CLEAR SIR CODES' command through On -Board diagnostics.

NOTES ON FAULT TREE

1. Checks Dual Pole Arming sensor for a shorted passenger reserve diode by measuring for voltage. If voltage can be measured, this indicated a shorted diode. This assumption is made because a diode approximates an open circuit unless biased to pass current.