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SRS-244

Diagnostic Trouble Code (DTC) SRS-234 and Diagnostic Trouble Code (DTC) SRS-244

DTC SRS-234 = Left seat belt tensioner, short-circuit to supply voltage
DTC SRS-244 = Right seat belt tensioner, short-circuit to supply voltage

Special tools:
- 998 8695
- Volvo Scan Tool (ST)

DTC conditions
If voltage in the circuit is high for over 10 seconds, the diagnostic trouble code (DTC) SRS-234 or SRS-244 are stored.

Cause of fault
Voltage too high.
- Short-circuit to supply voltage in SRS ignition cable or connectors between left or right seat belt tensioner and SRS sensor module.
- Short-circuit to supply voltage in left or right seat belt tensioner.

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). Calibrating Special Tool 998 8695
- Read off diagnostic trouble code (DTC).
- Clear diagnostic trouble code (DTC).
Diagnostic trouble codes (DTC) SRS-234 or SRS-244 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 Pyrotechnical Seat Belt Tensioner




- Ignition off.




- Disconnect battery negative lead.

For diagnostic trouble code (DTC) SRS-234:
- Remove left B-post pane. Pyrotechnical Seat Belt Tensioner - Replacement

For diagnostic trouble code (DTC) SRS-244:
- Remove right B-post panel. Pyrotechnical Seat Belt Tensioner - Replacement

For left and right seat belt tensioners:




- Fold back sill trim panel and disconnect connector from 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 checking.

Checking DTCs With The Seat Belt Tensioner Replaced By Special Tool 9988695




- Install special tool 9988695 to SRS ignition cable igniter connector.

NOTE: The special tool should be checked and faultless. If the tool is defective it will cause errors in the diagnosis and make fault-tracing harder. If in doubt check the special tool. Calibrating Special Tool 998 8695




- Switch ignition to position II.




- Connect battery negative lead.




- Read off diagnostic trouble code (DTC).
- Erase diagnostic trouble code (DTO). Diagnostic trouble codes (DTC) SRS-234 or SRS-244 can be erased if the fault is in the disconnected seat belt tensioner.

If the diagnostic trouble code (DTC) could be erased:
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 erased (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 to see if the SRS ignition cable is short-circuited to supply voltage.

Connecting Connector To The Pyrotechnical Seat Belt Tensioner




- Ignition off.




- Disconnect battery negative lead.




- Remove special tool 9988695.




- Connect 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 checking.

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-234 or SRS-244 should be stored if the fault is in the seat belt tensioner.

If diagnostic trouble code (DTC) SRS-244 or SRS-234 are obtained:
The short-circuit is in the seat belt tensioner.
^ Replace right or left seat belt tensione. Pyrotechnical 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 checking.

Disconnecting Connector From Pyrotechnical Seat Belt Tensioner




- Ignition off.




- Disconnect battery negative lead.




- Disconnect connector from 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 checking.

Checking To See If The SRS Ignition Cable Is Short-circuited To Supply Voltage




- Ignition off.




- Disconnect battery negative lead.




- Remove special tool 9988695.




- Disconnect battery positive lead.




- Switch ignition to position II.
Connect an ohmmeter between battery positive lead and connecting sockets on SRS ignition cable igniter connector.
- Connect one ohmmeter test terminal to the battery positive lead.
- Take an ohmmeter reading with the other test terminal against igniter connector terminal 1.




- Take an ohmmeter reading against "service hole" (see arrow in Figure) on the igniter connector.
The ohmmeter should read approx. 25 kohms or approx. 72 kohms.

NOTE: If the ohmmeter test pins are too big to fit into the connector terminal holes, insert a thin metal rod (or a piece of stripped cable) with a maximum diameter of 1 mm, and take readings from that. Take care not to damage the connector cable terminals.

If both readings are OK:
No permanent short-circuit to supply voltage in SRS ignition cable.
- Try to provoke any intermittent fault in the SRS ignition cable.

If the reading is abnormal:
If any of the ohmmeter readings are approx. 0 ohms there is a short-circuit to supply voltage in the SRS ignition cable or a short-circuit to supply voltage in the sensor module.
- Continue checking.

Checking To See If The SRS Ignition Cable Is Short-circuited To Supply Voltage




- Ignition off.




- Expose and remove SRS sensor module connector. SRS Sensor Module - Replacement





CAUTION: Never touch the sensor module pins. There is a risk of static discharge which could damage the sensor module.

NOTE: If the ohmmeter test pins are too big to fit into the sensor module connector, insert a thin metal rod (or a piece of stripped cable) with a maximum diameter of 1 mm, and take readings from that. Take care not to damage the connector cable terminals.

For left seat belt tensioner (diagnostic trouble code (DTC) SRS-233):




- Switch ignition to position II.




Connect an ohmmeter between battery positive lead and connecting sockets on the sensor module connector.
- Connect one ohmmeter test terminal to the battery positive lead.




- Take an ohmmeter reading with the other test terminal against sensor module connector terminal 1.
- Then take an ohmmeter reading against sensor module connector terminal 2.
The ohmmeter should read infinite resistance.

For right seat belt tensioner (diagnostic trouble code (DTC) SRS-243):
- Switch ignition to position II.
Connect an ohmmeter between battery positive lead and connecting sockets on the sensor module connector.
- Connect one ohmmeter test terminal to the battery positive lead.
- Take an ohmmeter reading with the other test terminal against sensor module connector terminal 3.
- Then take an ohmmeter reading against sensor module connector terminal 4.
The ohmmeter should read infinite resistance.

If the readings are OK for each seat belt tensioner:
The SRS ignition cable is OK.
^ Replace sensor module. SRS Sensor Module - Replacement

If the readings are abnormal for each seat belt tensioner:
If any of the ohmmeter readings is approx. 0 ohms there is a short-circuit to supply voltage in the SRS ignition cable.
^ Replace SRS cable harness.