LI54.21-P-070658
Service Bulletin Details
Public Details for: LI54.21-P-070658
A fixed srs message is displayed in the instrument cluster. Cause is not safety-relevant and does not affect function of safety systems.
- 2020 -
Models from 2020
SRS Message Displayed in Instrument Cluster Topic number LI54.21-P-070658 Version 4 Function group 54.21 Control units / basic modules Date 06-04-2020 Validity A-Class (177) CLA-Class (118) GLB-Class (247) Reason for change Updated Remedy, Validity and Part Number Reason for block Complaint: A fixed SRS message is displayed in the instrument cluster. Cause is not safety-relevant and does not affect function of safety systems. Cause: Higher resistance values at the SRS control unit connector for various SRS components (squibs, tensioners, pyrofuse, etc.). Complaint vehicles contain the stored fault code "There is an open circuit" for various squibs. Remedy: Note: If there are active/current faults or short circuit faults, this document does not apply. Further vehicle diagnosis is required. Fault-trace wire for affected component and ensure that there is no chafing or damaged areas. Ensure that all connections are secure and wires are firmly attached to connectors. If the inspection does not find a root cause, disconnect and reconnect the connectors to the SRS Control Unit. If the fault occurs again, or if this is a reoccurrence of the same problem, replace the SRS control unit. Ensure the new control unit is Q4 level or higher. NOTE: SRS control unit A177 900 0404 28 is available in very limited quantities, and may only be replaced if the fault returns again after first disconnecting and reconnecting of the connector to the SRS control unit. Only VOR orders will be allowed, so a unique VIN will be required for each order and demand will be closely monitored. MBUSA is counting on your collaboration to ensure parts availability of A177 900 0404 28 for customer complaints. Attachments File Description Q4 SRS Example.jpg Location of Q Level on SRS Control Unit Symptoms Body / Safety system / Airbag/Supplemental restraint system SRS / Indicator lamp / SRS indicator lamp / lit Body / Safety system / Seat belt / Seat belt indicator lamp / lit Body / Safety system / Airbag/Supplemental restraint system SRS / Indicator lamp / Airbag / lit 06-05-2020 7:06 PM © Copyright Mercedes-Benz AG MYNELSO Page 1/5 Control unit/fault code Control unit Fault code Fault text N2/10 - Supplemental restraint B000313 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the vent valve 'Driver airbag' has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B003813 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the right rear sidebag has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B001013 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the front passenger airbag (stage 1) has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B1B3613 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the emergency tensioning retractor at the center of the first seat row has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B275013 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the sidebag 'Driver' has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B284F13 system (SRS) (ORC177) (A (177),CLA (118)) The squib for pyrofuse 'High-voltage on-board electrical system' has a malfunction. There is an open circuit. (OCM177) N2/10 - Supplemental restraint B001213 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the vent valve 'Front passenger airbag' has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B001113 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the front passenger airbag (stage 2) has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B275113 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the sidebag 'Front passenger' has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B000113 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the driver airbag (stage 1) has a malfunction. There is an open circuit. (OCM177) N2/10 - Supplemental restraint B00E313 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the left rear emergency tensioning retractor has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B008013 system (SRS) (ORC177) (A (177),CLA (118)) The squib for belt force limiter 'Driver' has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B007913 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the emergency tensioning retractor 'Belt end fitting' (driver) has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B00E613 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the emergency tensioning retractor at the right of the third seat row has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B001313 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the front passenger kneebag has a malfunction. There is an open circuit. 06-05-2020 7:06 PM © Copyright Mercedes-Benz AG MYNELSO Page 2/5 N2/10 - Supplemental restraint B00E413 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the right rear emergency tensioning retractor has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B002113 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the left windowbag/headbag has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B007A13 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the emergency tensioning retractor 'Belt end fitting' (front passenger) has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B00E713 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the emergency tensioning retractor at the left of the third seat row has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B273513 system (SRS) (ORC177) (A (177),CLA (118)) The squib for pyrofuse 'On-board electrical network line' has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B002213 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the left rear window airbag/head airbag has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B000113 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the driver airbag (stage 1) has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B002A13 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the right rear window airbag/head airbag has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B007E13 system (SRS) (ORC177) (A (177),CLA (118)) The squib for emergency tensioning retractor 'Driver' has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B002913 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the right windowbag/headbag has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B1C1E13 system (SRS) (ORC177) (A (177),CLA (118)) The "Driver" seat occupancy recognition has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B000213 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the driver airbag (stage 2) has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B007F13 system (SRS) (ORC177) (A (177),CLA (118)) The squib for emergency tensioning retractor 'Front passenger' has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B003013 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the left rear sidebag has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B000413 system (SRS) (ORC177) (A (177),CLA (118)) The squib for the driver kneebag has a malfunction. There is an open circuit. N2/10 - Supplemental restraint B008213 system (SRS) (ORC177) (A (177),CLA (118)) The squib for belt force limiter 'Front passenger' has a malfunction. There is an open circuit. 06-05-2020 7:06 PM © Copyright Mercedes-Benz AG MYNELSO Page 3/5 Parts Part number ES1 ES2 Designation A17790004042 8 Quantity Note CONTROL UNIT, COMPLETE 1 EPC Not every repair requires replacement. Follow attached work instructions. Operation numbers/damage codes Op. no. Operation text Time Damage code Note 82485 73 Repair type 7 for exercising connector 82485 73 Repair type 1 for replacing SRS CU Attachments 06-05-2020 7:06 PM © Copyright Mercedes-Benz AG MYNELSO Page 4/5 Q4 SRS Example.jpg: 06-05-2020 7:06 PM © Copyright Mercedes-Benz AG MYNELSO Page 5/5