SRS-241
Diagnostic Trouble Code (DTC) SRS-231 and Diagnostic Trouble Code (DTC) SRS-241DTC SRS-231 = Left seat belt tensioner, short-circuit or capacitance too high
DTC SRS-241 = Right seat belt tensioner, short-circuit or capacitance too high
Special tools:
- 998 8695
- Volvo Scan Tool (ST)
DTC conditions
If resistance in the circuit is too low or capacitance too high for over 10 seconds, the diagnostic trouble code (DTC) SRS-231 or diagnostic trouble code (DTC) SRS241 is stored.
Cause of fault
Resistance too low.
- Short-circuit in SRS ignition cable or connectors between left or right seat belt tensioner and SRS sensor module.
- Short-circuit in left or right seat belt tensioner (resistance too low in igniter).
Capacitance too high.
- Capacitance too high or short-circuit in the SRS ignition cable igniter connector capacitor.
Fault symptoms
No symptoms apart from the SRS warning lamp coming on.
WARNING: There is a risk that the seat belt tensioner will not work if this DTC is posted.
Action
The fault can be found by a process of elimination.
WARNING: Under no circumstances use an ohmmeter or other live measuring instrument to take readings on a disconnected non-deployed pyrotechnical seat belt tensioner. This could deploy the seat belt tensioner.
NOTE: Follow the operations described in this chapter carefully and carry out operations in the correct order.
Checking Diagnostic Trouble Code (DTC) And Type Of Fault
Before starting to remove components, the Volvo Scan Tool (ST) should be used to check whether the fault is permanent or intermittent.
- Connect the Volvo Scan Tool (ST).
- Read off diagnostic trouble code (DTC).
- Clear diagnostic trouble code (DTC).
Diagnostic trouble codes (DTC) SRS-231 or SRS-241 cannot be cleared if the fault is permanent.
If diagnostic trouble code (DTC) could not be cleared (the fault persists):
The fault is permanent.
- Continue with disconnecting connector from pyrotechnical seat belt tensioner.
If the diagnostic trouble code (DTC) could be cleared:
The fault is not permanent. The fault could be intermittent.
Attempt to provoke the intermittent fault at every step of the fault tracing process by shaking connectors and cabling while taking readings.
- Continue with disconnecting connector from pyrotechnical seat belt tensioner.
Disconnecting Connector From Pyrotechnic Seat Belt Tensioner
- Make a note of radio code if anti-theft coded radio installed.
- Ignition off.
- Disconnect battery negative lead.
For left seat belt tensioner (diagnostic trouble code (DTC) SRS-231):
- Remove left B-pillar panel.
For right seat belt tensioner (diagnostic trouble code (DTC) SRS-241):
- Remove right B-pillar panel.
For left and right seat belt tensioners:
- Disconnect seat belt tensioner connector.
WARNING: Under no circumstances use an ohmmeter or other live measuring instrument to take readings on a disconnected non-deployed pyrotechnical seat belt tensioner. This could deploy the seat belt tensioner.
- Continue with checking DTCs with the seat belt tensioner replaced by special tool 9988695.
Checking DTCs With The Seat Belt Tensioner Replaced By Special Tool 9988695
- Connect special tool 9988695 to SRS ignition cable igniter connector.
NOTE: The special tool should be checked and faultless. If the tool is detective it will cause errors in the diagnosis and make fault tracing harder. If in doubt check the special tool.
- Switch ignition to position II.
- Connect battery negative lead.
- Read off diagnostic trouble code (DTC).
- Clear diagnostic trouble code (DTC). Diagnostic trouble codes (DTC) SRS-231 or SRS-241 can be cleared if the fault is in the disconnected seat belt tensioner.
If the diagnostic trouble code (DTC) could be cleared:
No fault detected by the SRS on-board diagnostic (OBD) system with the seat belt tensioner disconnected and replaced by special tool 9988695.
The fault is probably in the seat belt tensioner.
One last check should be made before replacing the seat belt tensioner.
- Continue with Connecting connector to the pyrotechnical seat belt tensioner.
If diagnostic trouble code (DTC) could not be cleared (the fault persists):
The fault persists even with the seat belt tensioner disconnected. This means that the seat belt tensioner is OK.
The fault is probably in the SRS ignition cable.
- Continue with checking SRS ignition cable resistance .
Connecting Connector To The Pyrotechnic Seat Belt Tensioner
- Ignition off.
- Disconnect battery negative lead.
- Remove special tool 9988695.
- Connect connector to seat belt tensioner.
WARNING: Under no circumstances use an ohmmeter or other live measuring instrument to take readings on a disconnected non-deployed pyrotechnical seat belt tensioner. This could deploy the seat belt tensioner.
- Continue with checking diagnostic trouble code (DTC) with the seat belt tensioner connected.
Checking Diagnostic Trouble Code (DTC) With The Seat Belt Tensioner Connected
- Switch ignition to position II.
- Connect battery negative lead.
- Read off diagnostic trouble code (DTC).
Diagnostic trouble codes (DTC) SRS-231 or SRS-241 should be stored if the fault is in the seat belt tensioner.
If diagnostic trouble code (DTC) SRS-241 or SRS-231 are obtained:
The short-circuit is in the seat belt tensioner.
^ Replace right or left seat belt tensioner. Pyrotechnic Seat Belt Tensioner - Replacement
If no diagnostic trouble code (DTC) is present:
The SRS on-board diagnostic (OBD) system has not detected a fault with the seat belt tensioner connected.
The fault could be intermittent in the SRS ignition cable.
- Continue with disconnecting connector from pyrotechnical seat belt tensioner.
Disconnecting Connector From Pyrotechnic Seat Belt Tensioner
- Ignition off.
- Disconnect battery negative lead.
- Disconnect seat belt tensioner connector.
WARNING: Under no circumstances use an ohmmeter or other live measuring instrument to take readings on a disconnected non-deployed pyrotechnical seat belt tensioner. This could deploy the seat belt tensioner.
- Install special tool 9988695.
- Continue with checking SRS ignition cable resistance.
Checking SRS Ignition Cable Resistance
- Ignition off.
- Disconnect battery negative lead.
For left seat belt tensioner (diagnostic trouble code (DTC) SRS-231):
- Remove left soundproofing panel and knee bolster.
- Remove socket housing A from connector 24/3.
- Ignition off.
- Connect an ohmmeter between connecting socket terminals 7 and 8 in socket housing A.
Take care not to damage connecting sockets.
The ohmmeter should read infinite resistance.
For right seat belt tensioner (diagnostic trouble code (DTC) SRS-241):
- Remove glove compartment.
- Remove socket housing B from connector 24/4.
- Ignition off.
- Connect an ohmmeter between connecting socket terminals 17 and 18 in socket housing B.
Take care not to damage connecting sockets.
The ohmmeter should read infinite resistance.
If the readings are OK for each seat belt tensioner:
The fault is probably in the SRS ignition cable between connectors 24/3 or 24/4 and the sensor module, or capacitance is too high in the SRS ignition cable igniter connector capacitor.
- Continue with checking resistance in the ignition cabling and sensor module.
If the readings are abnormal for each seat belt tensioner:
If the ohmmeter reads approx. 0 Ohms there is a short-circuit in the SRS ignition cable between connectors 24/3 or 24/4 and the igniter connector.
If the ohmmeter reads approx. 2-3 Ohms there is a short-circuit in the capacitor in the SRS ignition cable igniter connector.
^ Replace SRS cable harness.
Checking Resistance In The Ignition Cabling And Sensor Module
For left seat belt tensioner (diagnostic trouble code (DTC) SRS-231):
- Ignition off.
- Connect an ohmmeter between connecting pin terminals 7 and 8 in connector 2413 part A, where the disconnected socket housing was connected.
Take care not to damage connector pins.
The ohmmeter should read approx. 47 Kohms.
For right seat belt tensioner (diagnostic trouble code (DTC) SRS-241):
- Remove pin housing B from connector 24/4.
- Ignition off.
- Connect an ohmmeter between connecting pin terminals 17 and 18 in pin housing B.
Take care not to damage connector pins.
The ohmmeter should read approx. 47 Kohms.
If the readings are OK for each seat belt tensioner:
SRS ignition cable between connectors 24/3 or 24/4 and sensor module is OK.
There is a short-circuit in the SRS ignition cable between connectors 24/3 or 24/4 and the igniter connector.
^ Replace SRS cable harness.
If the readings are abnormal for each seat belt tensioner:
If the ohmmeter reads approx. 0 Ohms there is either a short-circuit in the SRS ignition cable between connectors 24/3 or 24/4 and the sensor module, or there is a short-circuit in the sensor module.
- Continue with checking SRS ignition cable resistance.
Checking SRS Ignition Cable Resistance
- Ignition off.
- Expose and remove SRS sensor module connector.
CAUTION: Never touch the sensor module pins. There is a risk of static discharge which could damage the sensor module.
For left seat belt tensioner (diagnostic trouble code (DTC) SRS-231):
- Ignition off.
- Connect an ohmmeter between connecting pin terminals 7 and 8 in connector 24/3 part A, where the disconnected socket housing was connected.
Take care not to damage connector pins.
The ohmmeter should read infinite resistance.
For right seat belt tensioner (diagnostic trouble code (DTC) SRS-241):
- Ignition off.
- Connect an ohmmeter between connecting pin terminals 17 and 18 in pin housing B.
Take care not to damage connector pins.
The ohmmeter should read infinite resistance.
If the readings are OK for each seat belt tensioner:
SRS ignition cable between connectors 24/3 or 24/4 and sensor module is OK.
^ Replace sensor module.
If the readings are abnormal for each seat belt tensioner:
If the ohmmeter reads approx. 0 Ohms there is a short-circuit in the SRS ignition cable between connectors 24/3 or 24/4 and the sensor module.
^ Replace SRS cable harness