SRS-221
Diagnostic Trouble Code (DTC) SRS-221 - Passenger Airbag, short-circuit or capacitance too highSpecial 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-221 is stored.
Cause of fault
Resistance too low.
- Short-circuit in the SRS ignition cable or connectors between passenger module and SRS sensor module.
- Short-circuit in passenger module (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 SRS passenger module 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 passenger module. This could deploy the airbag.
NOTE: Follow the operations described 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). Displaying & Reading Trouble Codes
- Read off diagnostic trouble code (DTC).
- Clear diagnostic trouble code (DTC).
It should not be possible to clear diagnostic trouble code (DTC) SRS-221 if the fault is permanent.
If diagnostic trouble code (DTC) SRS-221 could not be cleared (the fault persists):
The fault is permanent.
- Continue with Disconnecting passenger module connector.
If diagnostic trouble code (DTC) SRS-221 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 passenger module connector.
Disconnecting Passenger Module Connector
- Make a note of radio code if anti-theft coded radio installed.
- Ignition off.
- Disconnect battery negative lead.
- Remove glove compartment.
- Disconnect passenger module connector.
WARNING: Under no circumstances use an ohmmeter or other live measuring instrument to take readings on a disconnected non-deployed passenger module. This could deploy the airbag
Checking DTCs With The Passenger Module Replaced By Special Tool 998 8695
- Connect special tool 9988695 to SRS ignition cable igniter connector.
NOTE: The special tool should be checked and defect-free. 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).
- Clear diagnostic trouble code (DTC).
It should be possible to clear diagnostic trouble code (DTC) SRS-221 if the fault is in the passenger module.
If diagnostic trouble code (DTC) SRS-221 could be cleared:
No fault detected by the SRS on-board diagnostic (OBD) system with the passenger module disconnected and replaced by special tool 9988695.
The fault is probably in the passenger module. One last check should be made before replacing the passenger module.
- Continue with Installing passenger module connector.
If diagnostic trouble code (DTC) SRS-221 could not be cleared (the fault persists):
The fault persists even with the passenger module disconnected. This means that the passenger module is OK.
The fault is probably in the SRS ignition cable.
- Continue with Checking SRS ignition cable resistance.
Installing Passenger Module Connector
- Ignition off.
- Disconnect battery negative lead.
- Remove special tool 9988695.
- Connect connector to passenger module.
WARNING: Under no circumstances use an ohmmeter or other live measuring instrument to take readings on a disconnected non-deployed passenger module. This could deploy the airbag.
Checking Diagnostic Trouble Code (DTC) With The Passenger Module Connected
- Switch ignition to position II.
- Connect battery negative lead.
- Read off diagnostic trouble code (DTC).
If the fault is in the passenger module diagnostic trouble code (DTC) SRS-221 should be stored.
If diagnostic trouble code (DTC) SRS-221 is present:
There is a short-circuit in the passenger module.
^ Replace passenger module. Passenger Module Replacement
If no diagnostic trouble code (DTC) is present:
The SRS on-board diagnostic (OBD) system has not detected a fault with the passenger module connected.
The fault could be intermittent in the SRS ignition cable.
Disconnecting Passenger Module Connector
- Ignition off.
- Disconnect battery negative lead.
- Disconnect passenger module connector.
WARNING: Under no circumstances use an ohmmeter or other live measuring instrument to take readings on a disconnected non-deployed passenger module. This could deploy the airbag
- Install special tool 9988695.
Checking SRS ignition cable resistance
- Ignition off.
- Disconnect battery negative lead.
- Disconnect connector 24/33 on SRS ignition cable.
- Connect an ohmmeter between the terminal pins in the passenger module half of the connector 24/33 (part A in the figure).
Take care not to damage connector pins.
The ohmmeter should read infinite resistance.
If the reading is OK:
The fault is probably in the SRS ignition cable from the sensor module connector 24/33 or capacitance is too high in the capacitor in the SRS ignition cable igniter connector.
- Continue with Checking the resistance in the SRS ignition cable, SRS cable harness and sensor module.
If the reading is abnormal:
If the ohmmeter reads approx. 0 Ohms there is a short-circuit in the SRS ignition cable.
If the ohmmeter reads approx. 2-3 Ohms there is a short-circuit in the capacitor in the SRS ignition cable igniter connector.
^ Replace passenger module SRS ignition cable.
Checking the resistance in the SRS ignition cable, SRS cable harness and sensor module.
- Ignition off.
- Connect an ohmmeter between the connecting sockets in the sensor module half of the connector 24/33 (part B in the figure).
Take care not to damage connecting sockets.
The ohmmeter should read approx. 47 Kohms.
If the reading is OK:
SRS ignition cable in the SRS cable harness between connector 24/33 and the sensor module is OK.
^ Replace passenger module SRS ignition cable. Passenger Module Replacement
If the reading is abnormal:
If the ohmmeter reads approx. 0 Ohms there is a short-circuit in the SRS ignition cable in the SRS cable harness between the connector 24/33 and sensor module or there is a short-circuit in the sensor module.
Checking Resistance In The SRS Ignition Cable In The SRS Cable Harness
- 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.
- Connect an ohmmeter between the connecting sockets in the sensor module half of the connector 24/33 (part B in the figure).
Take care not to damage connecting sockets.
The ohmmeter should read infinite resistance.
If the reading is OK:
SRS ignition cable in the SRS cable harness between connector 24/33 and the sensor module is OK.
^ Replace sensor module. SRS Sensor Module - Replacement
If the reading is abnormal:
If the ohmmeter reads approx. 0 Ohms there is a short-circuit in the SRS ignition cable in the SRS cable harness between separated connector 24/33 and the sensor module.
^ Replace SRS cable harness.