Checking the integrity of the sensor and diagnostic module (SDM) (Chevrolet Captiva 1)

Contents: Checking the integrity of the sensor… ↧ Connected to power during operation… ↧

Use the following diagnostic chart if all circuits outside the sensing and diagnostic module (SDM) are normal as a result of running the appropriate diagnostic trouble code chart. This chart helps determine if the SDM needs to be replaced.

Description of the scheme

When the SDM detects a battery voltage greater than 9 V at SDM terminal 31, the air bag indicator lamp flashes seven times to confirm normal operation. At this time, the SDM performs initial checks, then measures resistances and switches to continuous monitoring.

When a malfunction is detected, the sensing and diagnostic module (SDM) stores a corresponding diagnostic trouble code (DTC) and illuminates the air bag warning lamp.

If the fault is no longer present and/or the ignition is switched off and on again, the SDM clears the current fault codes and writes them to the archive file, with the exception of codes B0052, B0053, B0055, B1000, B1001, B1019. The diagnostic tool does not clear these codes because they require replacement of the SDM. The SDM is replaced only after the fault that caused these fault codes to be stored has been corrected.

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

Caution! The sensing and diagnostic module (SDM) can retain sufficient voltage to deploy the air bags and pretensioners for 1 minute after the ignition is turned off and the fuse is removed. If the air bags and pretensioners are not disconnected, do not begin servicing until one minute has passed after disconnecting power from the SDM. Failure to do so could result in personal injury.

Attention! Handle the Sensor and Diagnostic module (SDM) very carefully during maintenance. Do not hit or shake the SDM. Never connect power to the Airbag Inflator system (SIR) unless the SDM is rigidly connected to the vehicle. In order for the Airbag Inflator system (SIR) to work correctly, all the mounting bolts of the SDM sensor and diagnostic module must be carefully tightened, and the arrow on the SDM must point towards the front of the vehicle. If the SDM module is not firmly attached to the vehicle, the included module may trigger, causing the airbags to release unexpectedly and causing 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 ensure that all components are installed correctly. Make sure the ignition key is in the off position for at least 30 seconds. When you turn on the ignition, watch the airbag indicator light. Did the light flash seven times?	-	Delete the diagnostic trouble codes for the Inflatable Airbag system (SIR) and go to "Checking the diagnostic system"	Go to Step 2
2	Turn the ignition key to the LOCK position and remove it. Connect the scan tool to the data link connector (DLC). Turn the ignition to the ON position. Read the diagnostic trouble codes of the inflatable airbag system using the diagnostic device. Is the same diagnostic fault code displayed as when the inflatable Airbag diagnostic system (SIR) was previously checked?	-	Go to Step 3.	Go to the table for the indicated diagnostic trouble code (DTC).
3	Clear diagnostic trouble codes for the airbag system. Turn off the ignition for at least 30 seconds. When you turn on the ignition, watch the airbag indicator light. Did the light flash seven times?	-	The system is normal	Go to Step 4
4	Turn the ignition key to the LOCK position and remove it. Disconnect the sensing and diagnostic module (SDM) connector. Replace the SDM module. Connect the sensing and diagnostic module (SDM) connector and make sure all components are installed correctly. Is the repair complete?	-	Go to item "Checking the diagnostic system".	-