Checking the integrity of the sensor and diagnostic module (SDM)

Use the following DTC if all circuits outside the sensing and diagnostic module are determined by running the appropriate DTC DTCs (SDM) serviceable. This card allows you to determine if the SDM needs to be replaced.

Circuit Description

When the SDM detects a battery voltage greater than 9V at terminal 31 of the SDM, the airbag warning lamp flashes seven times to confirm normal operation. In this case, the SDM performs initial checks, then measures the resistances and moves on to continuous monitoring.

When a malfunction is detected, the sensing and diagnostic module (SDM) writes the appropriate DTC (DTC) and turns on the airbag warning light.

If the fault is no longer observed and / or the ignition is turned off and on again, the SDM module erases the current fault codes and rewrites them in an archive file, with the exception of codes B0052, B0053, B0055, B1000, B1001, B1019. The scan tool does not clear these codes because they require an SDM replacement. The SDM should only be replaced after the fault that caused these DTCs has been corrected.

Checking the integrity of the sensor and diagnostic module (SDM)

Attention! Sensor and diagnostic module (SDM) can maintain sufficient voltage to deploy the airbags and pretensioners for 1 minute after the ignition is turned off and the fuse has been removed. If the airbags and pretensioners are not disconnected, do not start service until one minute has passed after disconnecting power from the SDM. Failure to do so may result in injury.

Attention! During maintenance, handle the sensing and diagnostics module (SDM) very careful. Do not hit or shake the SDM. Never connect power to the airbag system (SIR), if the SDM is not hardwired to the vehicle. To make the airbag system (SIR) is working correctly, all SDM sensor and diagnostic module mounting bolts must be properly tightened, and the arrow on the SDM must point towards the front of the vehicle. If the SDM is not securely attached to the vehicle, the enabled module may deploy, causing the airbags to deploy unexpectedly and may result in injury.

Step	Operation	Values	Yes	No
1	Turn the ignition key to the LOCK position and remove it. Connect all components of the airbag system and make sure that all components are installed correctly. Make sure the ignition key is in the off position for at least 30 seconds. Watch the airbag warning light when you turn on the ignition. Did the lamp flash seven times?	-	Clear Airbag System Diagnostic Trouble Codes (SIR) and go to point "Diagnostic system check"	Go to Step 2
2	Turn the ignition key to the LOCK position and remove it. Connect the diagnostic tool to the diagnostic socket (DLC). Set the ignition to the ON position. Read the diagnostic fault codes of the inflatable airbag system using a diagnostic device. Is the same diagnostic fault code displayed as in the previous check of the diagnostic system of airbags (SIR)?	-	Go to Step 3.	Go to the table for the specified DTC (DTC).
3	Clear the diagnostic trouble codes for the airbag system. Switch off the ignition for at least 30 seconds. Watch the airbag warning light when you turn the ignition on. Did the lamp flash seven times?	-	System OK	Go to Step 4
4	Turn the ignition key to the LOCK position and remove it. Disconnect the sensing and diagnostic module connector (SDM). Replace SDM. Plug in the sensor and diagnostic module connector (SDM) and make sure all components are mounted correctly. Is the repair finished?	-	Go to item "Diagnostic system check".	-

Connected to power during operation and start