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SRS AIR BAG DIAGNOSIS TSB Revision SUPPLEMENTAL RESTRAINT SYSTEM (SRS) 52B-33 CIRCUIT OPERATION • The SRS-ECU judges how severe a collision is by detecting signals from the left and right front • The ignition signal is input to the air bag module via the clock spring to inflate the air bag. DTC SET CONDITION • These DTC's are set if there is abnormal resis- tance between the input terminals of the driver's • The most likely causes for this code to be set are shown in the table below: . NOTE: *: The squib circuit connectors integrate a "short" spring (which prevents the air bag from deploying .) Therefore, if the connector (C-24, and D-18 and D-20) are damaged or improperly engaged, the short spring may not be released when the connector is connected. . TROUBLESHOOTING HINTS • Improper engaged connector or defective short spring* • Malfunction of the clock spring • Half-open circuit caused by improper clock spring neutral position • Damaged wiring harnesses or connectors • Malfunction of the driver's side air bag module (squib) • Malfunction of the SRS-ECU DIAGNOSIS Required Special Tools: • MB991958: Scan Tool (MUT-III Sub Assembly) • MB991824: Vehicle Communication Interface (V.C.I.) • MB991827: MUT-III USB Cable • MB991911: MUT-III Main Harness B • MB991865: Dummy resister • MB991866: Resister harness DTC SYMPTOM 21 • Short circuit in driver's side air bag module (squib) or harness • Short circuit in clock spring 22 • Open circuit in driver's side air bag module (squib) or harness • Open circuit in clock spring • Disconnection of driver's side air bag module (squib) connector • Half-open circuit caused by improper clock spring neutral position • Malfunction of connector contact 61 • Short circuit in driver's side air bag module (squib) harness leading to the power supply 62 • Short circuit in driver's side air bag module (squib) harness leading to the ground |