Open-Circuit Or Capacitance Too Low
Open-circuit or capacitance too low
Checking diagnostic trouble code (DTC) and type of fault
Hint: Before starting to remove components, the Volvo Scan Tool (ST) should be used to check whether the fault is permanent or intermittent.
Clear diagnostic trouble code (DTC).
Continue - Checking diagnostic trouble code (DTC) and type of fault, continuation
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Checking diagnostic trouble code (DTC) and type of fault, continuation
- Wait at least 10 seconds.
Read off diagnostic trouble code (DTC).
Diagnostic trouble code (DTC) SRS-232 cannot be cleared if the fault is permanent.
Can diagnostic trouble code (DTC) SRS-232 be cleared?
Yes - Diagnostic trouble code (DTC) could be cleared
No - Disconnecting connector from pyrotechnical seat belt tensioner
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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 - Disconnecting connector from pyrotechnical seat belt tensioner
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Disconnecting connector from pyrotechnical seat belt tensioner
Disconnecting connector from pyrotechnical seat belt tensioner
Disconnecting connector from pyrotechnical seat belt tensioner
- Make a note of radio code if anti-theft coded radio installed.
- Ignition off.
- Disconnect battery negative lead.
- Remove left/right B-pillar in accordance with Seat-belt tensioners, replacement Seat-Belt Tensioners, Replacement.
- 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 - CONTINUE
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Continue - Verification
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Checking DTCs with the seat belt tensioner replaced by special tool 998 8695
- Connect special tool 998 8695 TEST DEVICE 998 8695 Test Device to SRS ignition cable igniter connector.
Caution! 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.
- Ignition on.
- Connect battery negative lead.
Clear diagnostic trouble code (DTC).
Continue - Checking DTCs with the seat belt tensioner replaced by special tool 998 8695, continuation
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Checking DTCs with the seat belt tensioner replaced by special tool 998 8695, continuation
- Wait at least 10 seconds.
Read off diagnostic trouble code (DTC).
Diagnostic trouble code (DTC) SRS-232 can be cleared if the fault is in the disconnected seat belt tensioner.
Can diagnostic trouble code (DTC) SRS-232 be cleared?
Yes - Connecting connector to pyrotechnical seat belt tensioner
No - Checking SRS ignition cable connector
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Connecting connector to pyrotechnical seat belt tensioner
Connecting connector to pyrotechnical seat belt tensioner
Connecting connector to pyrotechnical seat belt tensioner
- Ignition off.
- Disconnect battery negative lead.
- Remove special tool 998 8695 TEST DEVICE 998 8695 Test Device.
- 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 - CONTINUE
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CONTINUE - Checking diagnostic trouble code (DTC) with the seat belt tensioner connected
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Checking diagnostic trouble code (DTC) with the seat belt tensioner connected
- Ignition on.
- Connect battery negative lead.
- Wait at least 10 seconds.
Read off diagnostic trouble code (DTC).
Diagnostic trouble code (DTC) SRS-232 should be stored if the fault is in the seat belt tensioner.
Is diagnostic trouble code (DTC) SRS-232 present?
Yes - Replacing component
No - Disconnecting connector from pyrotechnical seat belt tensioner
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Replacing component
The open-circuit is in the seat belt tensioner.
- Replace seat belt tensioner in accordance with Seat-belt tensioners, replacement Seat-Belt Tensioners, Replacement.
Continue - FAULT FOUND
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Disconnecting connector from pyrotechnical seat belt tensioner
- Make a note of radio code if anti-theft coded radio installed.
- 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 998 8695 TEST DEVICE 998 8695 Test Device.
Continue - Checking SRS ignition cable connector
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Checking SRS ignition cable connector
- Ignition off.
- Remove left soundproofing panel and knee bolster in accordance with Knee bolster, replacement Service and Repair.
- Remove socket housing A from connector 24/3.
- Check cable terminals in both the socket housing and corresponding pin housing, terminals 7 and 8 in connector 24/3A.
Caution! Cable terminals must not be damaged or pressed back.
- Connect the connector. Check that socket housing and pin housing lock into each other.
Are socket housing and pin housing OK?
Yes - Checking diagnostic trouble code (DTC) with the connector connected
No - Replacing component
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Replacing component
- Replace SRS cable harness.
Continue - FAULT FOUND
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Checking diagnostic trouble code (DTC) with the connector connected
- Ignition on.
- Connect battery negative lead.
- Clear diagnostic trouble code (DTC).
Continue - Checking diagnostic trouble code (DTC) with the connector connected, continuation
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Checking diagnostic trouble code (DTC) with the connector connected, continuation
- Wait at least 10 seconds.
- Read off diagnostic trouble code (DTC).
Diagnostic trouble code (DTC) SRS 232 cannot be cleared if the fault is still present.
Could the diagnostic trouble code (DTC) be cleared?
Yes - Replacing component
No - Checking the resistance in the ignition cable
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Replacing component
The SRS on board diagnostic (OBD) system has not detected a fault with connector 24/3A connected.
The fault is intermittent in the SRS ignition cable.
- Replace SRS cable harness.
Continue - FAULT FOUND
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Replacing component
If the ohmmeter reads infinity in any of the readings taken, there is an open circuit in the SRS ignition cable between connector 24/3 and the igniter connector.
Replace SRS cable harness.
Continue - FAULT FOUND
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Selecting measuring instrument
When checking igniter connector capacitor use either a resistance or capacitance measuring instrument
Hint: If you have a capacitance measuring instrument use this.
1. Measuring resistance.
2. Measuring capacitance.
Select one of the alternatives above.
1 - Checking igniter connector capacitor, measuring resistance
2 - Checking igniter connector capacitor, measuring capacitance
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Checking igniter connector capacitor, measuring resistance
- Ignition off.
- Connect measuring instrument terminals between the connector's service holes and terminal 2 right connecting pin. See connection in the figure. (The capacitor will charge.)
The ohmmeter reading should increase rapidly and stop at infinity.
- Reverse the position of the ohmmeter positive and negative terminals and connect them to the connector as above. See connection in the figure. (The capacitor will discharge and charge.)
The ohmmeter reading should drop rapidly to approx. 0 ohms and then increase to infinity.
Is the reading OK?
Yes - Checking resistance in the ignition cabling and sensor module
No - Replacing component
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Checking igniter connector capacitor, measuring capacitance
- A measuring instrument with a capacitance measuring facility can be used to check the capacitor in the SRS ignition cable igniter connector.
- Ignition off.
- Connect measuring instrument terminals between the connector service hole and terminal 2 right connecting pin. See connection in the figure. The measuring instrument should read between 0.46 F and 0.48 F.
Is the reading OK?
Yes - Checking resistance in the ignition cabling and sensor module
No - Replacing component
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Replacing component
The ohmmeter reading is constantly high without dropping or increasing there is an open circuit in the capacitor.
- Replace SRS cable harness.
Continue - FAULT FOUND
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Checking resistance in the ignition cabling and sensor module
- 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.
Caution! Take care not to damage connector pins.
The ohmmeter should read approx. 47 kohms.
Is the value OK?
OK - Replacing component
Not OK - Checking SRS sensor module connector
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Replacing component
SRS ignition cable between connector 24/3 and sensor module is OK. There is a fault (capacitance too low) in the SRS ignition cable igniter connector capacitor.
Replace SRS cable harness.
Continue - FAULT FOUND
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Checking SRS sensor module connector
- Ignition off.
- Expose and remove the SRS sensor module connector according to: Replacing the SRS sensor module Service and Repair
Caution! Never touch the sensor module pins. There is a risk of static discharge which could damage the sensor module.
- Check cable terminals in the female half of the connector and the male half of the sensor module.
Caution! Cable terminals must not be damaged or pressed back.
- Install and remove connector from sensor module. Check that the connector locks into the sensor module.
1. Female and male connector halves are OK.
2. Male sensor module connector half is defective.
3. Female connector half is defective.
Select one of the above alternatives.
1. - Checking SRS ignition cable resistance
2. - Replacing component
3. - Replacing component
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Replacing component
Replace the sensor unit according to: Replacing the SRS sensor module Service and Repair
Continue - FAULT FOUND
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Replacing component
Replace SRS cable harness.
Continue - FAULT FOUND
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Checking SRS ignition cable resistance
Caution! Never touch the sensor module pins. There is a risk of static discharge which could damage the sensor module.
- Ignition off.
Connect an ohmmeter between sensor module connector terminal 1 and connector 24/3 part A connecting pin terminal 7, where the disconnected socket housing was connected.
The ohmmeter should read approx. 0 ohms.
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 (0.04"), and take readings from that. Take care not to damage the connector cable terminals.
Connect an ohmmeter between sensor module connector terminal 2 and connector 24/3 part A connecting pin terminal 8, where the disconnected socket housing was connected.
The ohmmeter should read approx. 0 ohms.
Are both readings OK for the seat belt tensioner?
Yes - Replacing component
No - Replacing component
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Replacing component
SRS ignition cable between connector 24/3 and sensor module is OK.
Replace the sensor unit according to: Replacing the SRS sensor module Service and Repair
Continue - FAULT FOUND
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Replacing component
If the ohmmeter reads infinity in any of the readings taken, there is an open circuit in the SRS ignition cable between connector 24/3 and the sensor module connector.
Replace SRS cable harness.
Continue - FAULT FOUND
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Checking the resistance in the ignition cable
- Ignition off.
- Disconnect the battery negative lead.
- Remove special tool: 998 8695 TEST DEVICE 998 8695 Test Device
- Remove socket housing A from connector 24/3.
Connect an ohmmeter between terminal socket 7 in removed socket housing A and igniter connector terminal 1.
The ohmmeter should read 0 ohms.
Note! If the ohmmeter test pins are too large to fit in the connector's terminal hole, install a narrow metal pin (or a stripped piece of cable) max. diameter 1 mm. Measure against the metal pin or the piece of cable with the test pin. Do not damage the connector's cable terminal.
Connect an ohmmeter between terminal socket 8 in socket housing A and service hole (see arrow in illustration) on igniter connector.
The ohmmeter should read 0 ohms.
Are the values OK for the seat belt pre-tensioner?
Yes - Selecting measuring instrument
No - Replacing component
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