B0018

Diagnostic Chart 1 Of 2:

Diagnostic Chart 2 Of 2:

Schematics:

CIRCUIT DESCRIPTION
When you first turn ON the ignition, 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 RUNNING THE DTC
Deployment loop voltage out of range test - Ignition 1 voltage is within the normal operating voltage range.

Deployment loop resistance measurement test
^ Ignition 1 voltage is within the normal operating voltage range.
^ Passenger frontal deployment loop is not shorted to voltage.

CONDITIONS FOR SETTING THE DTC
Deployment loop voltage out of range test - Passenger frontal high terminal A3 is more than 6 volts for 300 milliseconds.

Deployment loop resistance measurement test - Passenger frontal high terminal A3 is less than 2 volts AND passenger frontal deployment loop resistance is less than 6 ohms for 300 milliseconds.

ACTION TAKEN WHEN THE DTC SETS
The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.

CONDITIONS FOR CLEARING THE DTC
^ You can issue a CLEAR CODES command
^ A history DTC will clear once 255 malfunction free ignition cycles have occurred

DIAGNOSTIC AIDS
A short to B+ or a short to ground condition in the inflatable restraint IP module deployment loop can cause an intermittent condition. Inspect the passenger frontal high and passenger frontal low circuits 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 inline connector C216.
5. This step isolates the malfunction to one side of C216.
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 the passenger frontal high circuit.
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 and all communication DTCs