B0018

When measurements are requested in the diagnostic charts, use SA91114NE digital multimeter with correct terminal adapter from SA9206Z. When a check for proper connection is requested, refer to "Intermittent and Poor Connections". When a wire connector or terminal repair is requested, use the proper repair parts and refer to "Wire Repair" procedure.

CAUTION: BE CAREFUL WHEN YOU HANDLE A SENSING AND DIAGNOSTIC MODULE (SDM). DO NOT STRIKE OR JOLT THE SDM. BEFORE APPLYING POWER TO THE SDM:
^ REMOVE ANY DIRT, GREASE, ETC. FROM THE MOUNTING SURFACE.
^ POSITION THE SDM HORIZONTALLY ON THE MOUNTING SURFACE
^ TIGHTEN ALL OF THE SDM FASTENERS AND SDM BRACKET FASTENERS TO THE SPECIFIED TORQUE VALUE.

FAILURE TO FOLLOW THE CORRECT PROCEDURES COULD CAUSE AIR BAG DEPLOYMENT, PERSONAL INJURY OR UNNECESSARY SIR SYSTEM REPAIRS.

DTC B0018 - Diagnostic Chart (Chart 1 Of 2):

DTC B0018 - Diagnostic Chart (Chart 2 Of 2):

CIRCUIT DESCRIPTION

Schematic:

When the ignition switch is turned On and during vehicle operation, the SDM performs tests to detect system faults. One test the SDM performs is to monitor the passenger deployment loop high circuit and passenger deployment loop low circuit voltage difference. By monitoring voltage, the SDM is able to detect when loop voltage is not between 2.4 and 6.0 Volts.

DTC PARAMETERS:
DTC B0018 can be set when the passenger loop voltage is out of range. The following conditions must be met to set this DTC.
^ Ignition voltage is present at the SDM and continuous.
^ The passenger deployment loop voltage is over 6 Volts or under 2.4 Volts and deployment loop resistance is under 6 Ohms.
^ Fault is present for half a second.

ACTION TAKEN:
^ DTC B0018 will set.
^ The air bag telltale will be On.

DIAGNOSTIC AIDS:
^ When attempting to diagnose an intermittent passenger loop fault, use the Scan tool to monitor current DTCs. Wiggle wires and check connections while watching for a current DTC to appear and/or disappear on Scan tool.
^ Always start diagnosis of SIR DTCs with an Inspection of wiring and components for visible damage.
^ A short to ground in circuits 1403 or 1404 could cause this DTC.
^ A short between circuits 1403 or 1404 and another vehicle circuit could cause this DTC.
^ Always perform the "SIR Diagnostic System Check" procedure before using this chart. Diagnostic System Check