B1018

NOTICE: When DTC B1018 has been set, it is necessary to replace the Sensing and Diagnostic Module (SDM). Setting DTC B1018 will also cause DTC B1071 to set. When a scan tool clear codes command is issued and the malfunction is no longer present, DTC B1018 and DTC B1071 will remain current. Make sure that the short to ground condition is repaired prior to installing a replacement SDM to avoid damaging the SDM.

When measurements are requested in this table, use J 39200 DVM with the correct terminal adapter from J 35616-A CONNECTOR TEST ADAPTER KIT. When a check for proper connection is requested, refer to INTERMITTENTS AND POOR CONNECTIONS in Diagrams. When a wire, connector or terminal repair is requested, use J 38125-A TERMINAL REPAIR KIT and refer to WIRING REPAIR. Service and Repair


CIRCUIT DESCRIPTION

When you first turn the ignition switch to the RUN position, the SDM performs tests to diagnose critical malfunctions within itself. Upon passing these tests, IGNITION 1, 23 VLR and deployment loop voltages are measured to make sure they are within their respective normal voltage ranges. The SDM monitors the voltages at DRIVER SIDE LOW terminal 3 and PASSENGER SIDE LOW terminal 4 to detect shorts to ground in the inflator module circuits. The service wait time is 10 minutes. Service and Repair
for enable/disable procedures.

CONDITIONS FOR SETTING THE DTC

^ The driver deployment loop is not open.
^ The passenger deployment loop is not open.
^ The driver deployment is not shorted to voltage.
^ The voltage at DRIVER SIDE LOW terminal 3 is more than 3.3 volts.
^ The voltage at PASSENGER SIDE LOW terminal 4 is less than 3.3 volts for 500 milliseconds.
The following tests check for this DTC. These tests occur when IGNITION 1 is within the normal operating voltage range.
^ POWER-ON--When the malfunction is detected in this test, the RESISTANCE MEASUREMENT test will not be performed.
^ CONTINUOUS MONITORING.


ACTION TAKEN WHEN THE DTC SETS

^ The SDM sets DTC B1018 and also DTC B1071.
^ The SDM turns ON the AIR BAG warning lamp.

CONDITIONS FOR CLEARING THE DTC

DTC B1018 is a latched code. You cannot clear a latched code. Repair the malfunction that set this DTC before you replace the SDM.

DIAGNOSTIC AIDS

A short-to-ground in the inflatable restraint I/P module circuit can cause an intermittent condition. A DTC B1018 would be accompanied by DTC B1071. Inspect CKTs 1403 and 1404 carefully for cutting or chafing. Wiring pigtail damage requires replacement of the inflatable restraint I/P module. A careful inspection of the circuits and components indicated on the DTC B1018 Table is essential in order to prevent damage to the replacement SDM.

The diagnostic table directs the technician to note the entry value of PASSENGER SENSELO. Comparing the value of PASSENGER SENSELO can be helpful in determining if an intermittent condition exists.

DTC TABLE TEST DESCRIPTION

Number(s) below refer to step number(s) on the diagnostic table.
2. This test determines the passenger side low voltage measured by the SDM.
3. This test isolates the malfunction to one side of the inflatable restraint I/P module yellow 2-way connector located under RH I/P. This is done by substituting the known good resistance of the load tool and then observing if the malfunction is still present.
5. This test determines whether the malfunction is in CKT 1403.
7. This test determines whether the malfunction is in CKT 1404.