This manual provides comprehensive service and repair information for the Supplemental Restraint System (SRS) Airbag, Safety Belts, and Bunk Restraints found in VN Series and VHD Series models. Trucks have a long-standing commitment to safety, and these heavy-duty vocational and long-haul truck platforms reflect decades of innovation in occupant protection. This guide is designed to assist Dealerships, independent repair shops, fleet maintenance technicians, and knowledgeable owners in maintaining the critical safety systems that ensure occupant well-being. The content covers a wide range of components, including airbag modules, control units, contact reels, wiring harnesses, seat belts, and bunk restraints, with an emphasis on accurate diagnosis and repair to uphold safety standards.
The scope of this manual is focused on the detailed diagnostics, troubleshooting, and repair procedures for the SRS and associated restraint systems in VN and VHD series trucks. It includes guidance on interpreting specific diagnostic trouble codes (DTCs) such as MID 232 SID 254, SID 1, and SID 240, as well as non-code fault diagnosis for SRS lamp issues. The manual outlines component replacement procedures for items like airbag modules, ECUs, seat belts, and bunk restraints, and provides crucial technical data including wiring diagrams and torque specifications. By offering in-depth, manufacturer-specific guidance, this manual empowers technicians to perform precise repairs, ensuring the continued safety and compliance of these vital vehicle systems.
Service Manual Volvo Trucks
THIS MANUAL COVERS THE FOLLOWING SUBJECTS:
SRS Airbag
Safety Belts
Bunk Restraints
FOR MODELS : VN & VHD
Contents
General
SRS Airbag, Safety Belts and Bunk Restraints
Specifications
SRS Components, Torque Values
Safety Belts and Bunk Restraints, Torque Values
Tools
Special Tools
Other Special Equipment
Design and Function
Safety Belts and Bunk Restraints
Supplemental Restraint System (SRS)
System Overview
Supplemental Restraint System (SRS) Components
SRS Control Unit (ECU)
Control Unit Connector
Airbag Module
Airbag Module Connector
Contact Reel
SRS Indicators (vehicles built prior to 3/99)
SRS Indicators (vehicles built from 3/99)
Diagnostic System with Fault Codes 7
SRS Wiring Harness
Supplemental Restraint System (SRS) Wiring Diagram
Troubleshooting
General Work Practices
Test Resistor, Checking
Connecting the Test Resistor
Reading Fault Codes
MID 232 SID 254 FMI 12 Airbag Control Unit,
Component Failure
MID 232 SID 1 FMI 6 Igniter Loop, Current
High/Short Circuit
MID 232 SID 1 FMI 5 Igniter Loop, Current
Low/Open Circuit
MID 232 SID 1 FMI 4/3 Igniter Loop, Voltage
Shorted Low/High
MID 232 SID 240 FMI 14 SRS Airbag, Crash
Data Stored
Faults Which Do Not Generate a Fault Code
SRS Lamp Does not Light 44
SRS Lamp Does not Light and Not Responding
Message in Diagnostic Display
The SRS Lamp is Lighting but no Fault Code is
Stored
Routines for a Damaged/Faulty Airbag Module
Safety Belts and Bunk Restraints, Inspection
Service Procedures
General Work Practices
After the Airbag Deploys
Airbag Module/Contact Reel, Replacement
SRS ECU, Replacement
SRS Wiring Harness, Replacement
Safety Belt, Replacement (One)
National Seat
Safety Belt, Replacement (One)
Volvo Seat
Lower Bunk Restraint, Replacement
VN 420/610/660
Lower Bunk Restraint, Replacement
VN 770
Upper Bunk Restraint, Replacement
VN 610/660
Upper Bunk Restraint, Replacement
VN 770
Service Manual Volvo Trucks
THIS MANUAL COVERS THE FOLLOWING SUBJECTS:
SRS Airbag
Safety Belts
Bunk Restraints
FOR MODELS : VN & VHD
Contents
General
SRS Airbag, Safety Belts and Bunk Restraints
Specifications
SRS Components, Torque Values
Safety Belts and Bunk Restraints, Torque Values
Tools
Special Tools
Other Special Equipment
Design and Function
Safety Belts and Bunk Restraints
Supplemental Restraint System (SRS)
System Overview
Supplemental Restraint System (SRS) Components
SRS Control Unit (ECU)
Control Unit Connector
Airbag Module
Airbag Module Connector
Contact Reel
SRS Indicators (vehicles built prior to 3/99)
SRS Indicators (vehicles built from 3/99)
Diagnostic System with Fault Codes 7
SRS Wiring Harness
Supplemental Restraint System (SRS) Wiring Diagram
Troubleshooting
General Work Practices
Test Resistor, Checking
Connecting the Test Resistor
Reading Fault Codes
MID 232 SID 254 FMI 12 Airbag Control Unit,
Component Failure
MID 232 SID 1 FMI 6 Igniter Loop, Current
High/Short Circuit
MID 232 SID 1 FMI 5 Igniter Loop, Current
Low/Open Circuit
MID 232 SID 1 FMI 4/3 Igniter Loop, Voltage
Shorted Low/High
MID 232 SID 240 FMI 14 SRS Airbag, Crash
Data Stored
Faults Which Do Not Generate a Fault Code
SRS Lamp Does not Light 44
SRS Lamp Does not Light and Not Responding
Message in Diagnostic Display
The SRS Lamp is Lighting but no Fault Code is
Stored
Routines for a Damaged/Faulty Airbag Module
Safety Belts and Bunk Restraints, Inspection
Service Procedures
General Work Practices
After the Airbag Deploys
Airbag Module/Contact Reel, Replacement
SRS ECU, Replacement
SRS Wiring Harness, Replacement
Safety Belt, Replacement (One)
National Seat
Safety Belt, Replacement (One)
Volvo Seat
Lower Bunk Restraint, Replacement
VN 420/610/660
Lower Bunk Restraint, Replacement
VN 770
Upper Bunk Restraint, Replacement
VN 610/660
Upper Bunk Restraint, Replacement
VN 770
