SDM turns “ON” the “AIR BAG” warning lamp and sets a diagnostic trouble code. The voltage difference between “Driver Bag High” terminal “3” and “Driver Bag Low” terminal “4” is above orĮqual to a specified value for 500 milliseconds during “Continuous Monitoring.”
DRIVER SIDE DEPLOYMENT LOOP OPEN DRIVER
By monitoring the voltage difference between “Driver Bag High” and “Driver Bag Low”, the SDM calculates the combined resistance of the driver air bag assembly, SRS coil assembly, harness wiring CKTs IB05–YEL and IB06–YEL/BLK, and connector terminal contact. This produces proportional voltage drops in the loop.
During “Continuous Monitoring” diagnostics, a fixed amount of current is following in the deployment loop. Upon passing these tests, “ignition 1”, and deployment loop voltages are measured to ensure they are within their respective normal voltage ranges. When the ignition switch is turned “ON”, the SDM will perform tests to diagnose critical malfunctions within itself. Is passenger sense LO less than 3.5 volts? Measure resistance on SDM harness connector from terminal “4” to terminal “12” (Ignition 1).ġ. Ignition switch “OFF.” 2. Connect SRS driver / passenger load tool J–41433 andĪppropriate adapter J–35616–A to driver air bag assembly harness connector located of top of the steering column.ģ. Reconnect SRS coil assembly harness connector as the baseġ. Reconnect all components, ensure all components are 4. Measure resistance on SDM harness connector from terminal 3. Disconnect SRS drive / passenger load tool. Connect SRS driver / passenger load tool J–41433 and appropriate adapter to SRS coil assembly harness connector.ġ. Ignition switch “OFF.” 2. Disconnect SDM. Leave passenger air bag assembly connected. Given in the scan tool operator’s manual.Ĥ. Ignition switch “ON.” 5. Read driver sense LO.ġ. Ignition switch “OFF.” 2. Disconnect SRS coil assembly yellow 2–pin connector at theīase of the steering column. Was the “SRS Diagnostic System Check” performed?ġ. When measurements are requested in this chart use J–39200ĭVM with correct terminal adapter from J–35616–A.Ģ. Ignition switch “OFF.” 3. Connect scan tool data link connector. When a scan tool “CLEAR CODES” command is issued and the malfunction is no longer present, DTC 71 will remain current. Ensure that the short to voltage condition is repaired prior to installing a replacement SDM to avoid damaging the SDM. Setting DTC 25 will also cause DTC 71 to set. This test determines whether the malfunction is inĭTC 25 Driver Deployment Loop Short To IgnitionĬAUTION: When DTC 25 has been set, it is necessary to replace the SDM.
This test determines whether the malfunction is inĥ. SRS coil assembly yellow 2–pin connector at the base of steering column.Ĥ. This test isolates the malfunction to one side of the This test determines whether the SDM isģ. Number(s) below refer to step number(s) on the diagnostic chart: 2.
SDM turns “ON” the “AIR BAG” warning lamp and sets DTC 25 and also DTC 71 Once these conditions are met and the voltage at “Driver Bag Low” is above a specified value, DTC 25 will set. This test is run once each ignition cycle and “Continuous Monitoring”. “Ignition 1” is in the normal operating voltage range. The SDM monitors the voltage at “Driver Bag Low” terminal “4” and “Passenger Bag Low” terminal “16” to detect shorts to B+ in the air bag assembly circuits. DTC 25 Driver Deployment Loop Short To Voltage