B1018

Circuit Description
When you first turn the ignition switch to the ON position, the Inflatable Restraint Sensing and Diagnostic Module (SDM) performs tests to diagnose critical malfunctions within itself. Then the SDM performs the following continuous diagnostic tests on the deployment loops:
^ Deployment loop voltage out of range test
^ Deployment loop resistance measurement test If the voltage out of range test detects a short to voltage condition, the resistance measurement test for that deployment loop will not be performed.

Conditions for Setting the DTC
^ Deployment loop voltage out of range test.
- Ignition 1 voltage is within the normal operating voltage range.
- Passenger frontal high terminal A3 is more than 6 volts for 500 milliseconds.
^ Deployment loop resistance measurement test.
- Ignition 1 voltage is within the normal operating voltage range.
- Passenger frontal deployment loop is not shorted to voltage.
- Passenger frontal high terminal A3 is less than 2 volts AND passenger frontal deployment loop resistance is less than 4.5 ohms for 500 milliseconds.

The passenger frontal deployment loop consists of the following components:
^ Inflatable restraint Instrument Panel (IP) module.
^ Harness wiring of the passenger frontal high circuit.
^ Harness wiring of the passenger frontal low circuit.
^ Connector terminal contact.

Action Taken When the DTC Sets
^ The SDM sets a DTC B1018.
^ The SDM turns ON the AIR BAG warning indicator.

Conditions for Clearing the DTC
^ Current DTC
- Deployment loop voltage out of range test- passenger frontal high terminal AS is 6 volts or less for 500 milliseconds.
- Deployment loop resistance measurement test-passenger frontal high terminal AS is 2 volts or more AND passenger frontal deployment loop resistance is less than 4.5 ohms for 500 milliseconds.
^ History DTC
- Issue a scan tool CLEAR CODES command.
- Once 250 malfunction free ignition cycles have occurred.

Diagnostic Aids
A short to B+ or short to ground in the Inflatable Restraint IP Module circuit can cause an intermittent condition. Inspect the passenger frontal high circuit and the passenger frontal low circuit carefully for cutting or chafing. Wiring pigtail damage requires replacement of the Inflatable Restraint IP Module.

Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
2. This step checks the Inflatable Restraint Steering Wheel Module yellow 2-way connector.
5. This step checks to see if there is a malfunctioning Inflatable Restraint IP Module.
7. This step checks to see if there is a short to ground in the passenger frontal high circuit.
9. This step checks to see if there is a short to ground in the passenger frontal low circuit.
11. This step checks to see if there is a short to B+ in
13. This step determines if there is a short to B+ in the passenger frontal low circuit or if there is a malfunctioning SDM.
16. This step clears all SIR DTCs.