Checking Communication With The SRS Control Module
Checking communication with the SRS control module
Checking communication with the ABS system
- Ignition off.
- Connect Volvo Scan Tool (ST) to data link connector (DLC).
- Ignition on.
- Power up the Volvo Scan Tool (ST).
Try to establish communication with the ABS system.
Has communication with the ABS system been established?
Yes - Checking wiring
No - Checking the Volvo Scan Tool (ST)
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Checking wiring
- Ignition off.
- Disconnect the Volvo Scan Tool (ST) from data link connector (DLC).
- Disconnect the battery negative lead.
- Disconnect the control module.
Check the cable between control module 9 and data link connector (DLC) 7 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault or a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Connect an ohmmeter between the battery positive terminal and data link connector (DLC) 7. Check for a short-circuit to supply voltage Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check the connectors for contact resistance and oxidation. Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Remedy as necessary.
Other information
- The voltage at control module connector 9 should be approximately 10 V.
- To access / replace the control module, see Replacing the SRS module Service and Repair.
Was an open-circuit found?
Yes - Verification
No - Checking the power supply to the control module
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Checking the power supply to the control module
- Ignition on.
Take a reading with a voltmeter between control module connector 5 and ground.
The voltmeter should read battery voltage.
OK - Replacing the component
Not OK - SRS-129
Fault-trace according to Signal too low. Permanent fault Signal Too Low. Permanent Fault.
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Replacing the component
Try replacing the control module according to Replacing the SRS module Service and Repair.
Select Continue when the fault has been remedied.
Continue - Verification
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Checking the Volvo Scan Tool (ST)
Check the Volvo Scan Tool (ST), the power supply and ground for the data link connector (DLC).
Were any faults found?
Yes - Verification
No - Checking the communication cable for the ABS system.
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Checking the communication cable for the ABS system.
- If there is no communication with the ABS system, there is a fault in the circuit between the control modules in the circuit and the data link connector (DLC).
- Check data link connector (DLC) for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Check data link connector (DLC) connector 7 and the connected control modules for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault , short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault and for an open circuit, according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault
Hint: For further information about the circuit for the data link connector (DLC), see the appropriate Wiring Diagram.
If no faults are found, check the Volvo Scan Tool (ST).
Remedy as necessary.
Other information:
- To access / replace the control module, see Replacing the SRS module Service and Repair.
Select Continue when the fault has been remedied.
Continue - Checking the communication cable for the ABS system, continued
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Checking the communication cable for the ABS system, continued
- Ignition on.
- Check data link connector (DLC) connector 7 and ground control modules for a short-circuit to voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Remedy as necessary.
Other information:
- The voltage in the communication cable should be approximately 9-11 V with the ignition on. This applies if the fault-tracing instrument is not connected.
- To access / replace the control module, see Replacing the SRS module Service and Repair.
Select Continue when the fault has been remedied.
Continue - Verification
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Verification
Verification
Hint: After repairs have been completed they must be verified as follows to ensure that the fault has been eliminated:
- Ignition off.
- Reinstall the components, reconnect the connectors etc.
- Ignition on.
Try to establish communication with the SRS system.
Has contact been established?
Yes - VERIFIED
No - VERIFICATION FAILED
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VERIFIED - FAULT FOUND
VERIFICATION FAILED - Fault-tracing information
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Fault-tracing information
Information
Fault-tracing information
The fault should be diagnosed and remedied. Since this is not the case the fault-tracing process has failed.
Complete the fault-tracing for those fault or try again.
Do you want to terminate fault-tracing at this time?
Yes - Exit fault-tracing
No - Attempt New Test
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Attempt New Test - Checking communication with the ABS system
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SRS-129
Signal too low. Permanent fault
Checking component
Hint: The battery should be checked for loose terminal connections or low battery voltage before starting fault-tracing. If the battery voltage is too low, check the charging system for too low battery voltage.
Continue - Checking the connector
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Checking the connector
- Make a note of the anti-theft radio code.
- Ignition off.
- Disconnect the battery negative lead.
- Disconnect the control module connectors.
- Check the control module connector for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault and a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check for damage carefully.
- Connect the battery negative lead.
- Ignition on.
Connect an voltmeter between control module 5 and ground. Measure the voltage. The voltmeter should read battery voltage if there is no open-circuit or short-circuit to ground.
Remedy as necessary.
Other information:
- To disconnect / replace the control module, see Replacing the SRS module Service and Repair.
Select Continue when the fault has been remedied.
Continue - Verification
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Verification
Verification
Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off.
- Reinstall the connectors, components etc.
- Ignition on.
- Read off diagnostic trouble codes (DTCs).
If the DTC status changed to intermittent it means that the fault is no longer present.
Does the status change?
Yes - VERIFIED
No - VERIFICATION FAILED
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VERIFIED - FAULT FOUND
VERIFICATION FAILED - Fault-tracing information
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Fault-tracing information
Information
Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.
Do you want to exit fault-tracing?
Yes - Exit fault-tracing
No - Attempt New Test
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Attempt New Test - Checking component
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VERIFIED - FAULT FOUND
VERIFICATION FAILED - No Fault Found
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