DTC 18

DTC 18 Passenger Deployment Loop Short To Ground




Circuit Description:
When the ignition switch is turned "ON", the Sensing and Diagnostic Module (SDM) will perform tests to diagnose critical malfunctions within itself. Upon passing these tests, "ignition 1", and deployment loop voltages are measured to ensure they are within their respective normal voltage ranges.
The SDM monitors the voltages at "Driver Bag Low" terminal "4" and "Passenger Bag Low" terminal "16" to detect short to ground in the air bag assembly circuits.

DTC Will Set When:
Neither of the two air bag assemblies is open. "Ignition 1" is within the normal operating voltage range. Once these conditions are met and the voltage at "Passenger Bag Low" is below a specified value, Diagnostic Trouble Code (DTC) 18 will set. This test is run once each ignition cycle and "Continuous Monitoring".

Action Taken:
SDM turns "ON" the "AIR BAG" warning lamp and sets a diagnostic trouble code.

DTC Will Clear When:
This malfunction is no longer occurring and the ignition switch is turned "OFF".

DTC 18 (Steps 1 - 6):

DTC Chart Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart:

2. This test determines whether the SDM is malfunctioning.
3. This test isolates the malfunction to one side of the passenger air bag assembly yellow 2-pin connector behind glove box compartment.
4. This test determines whether the malfunction is in Circuit(CKT) IB07-YELLOW/GREEN.
5. This test determines whether the malfunction is in CKT IB08-YELLOW/RED.

Diagnostic Aids:
An intermittent condition is likely to be caused by a short to ground in the passenger air bag assembly circuit. Inspect CKTs IB07-YELLOW/GREEN and IB08-YELLOW/RED carefully for cutting or chafing. If the wiring pigtail of the passenger air bag assembly is damaged, the component must be replaced.