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Signal Too Low. Permanent Fault






Signal too low. Permanent fault

Checking the power supply








- Ignition off
- Disconnect the seat belt buckle connector
- Check the seat belt buckle connector. Check for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault
- Ignition on.
Check that there is supply voltage at connector terminal #1.
Remedy as necessary.

Other information
- To access and replace the seat belt buckle, see Seat belt buckle Seat Belt Buckle.









Is there supply voltage?

Yes - Checking the connector and cable

No - Checking the connector and cable

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Checking the connector and cable








- Ignition off
- Disconnect the battery negative lead
- Disconnect the control module connector
- Disconnect the seat belt buckle connector
- Connect the battery negative lead.

Warning! There must not be anyone inside the passenger compartment when the battery is connected.

Measure the resistance between seat belt buckle connector terminal #2 and control module connector terminal #70 (#45). Check for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
The resistance must be 0 ohms. If not there is an open-circuit.
Measure the resistance between seat belt buckle connector terminal #2 and the battery positive terminal. Measure the resistance between control module connector terminal #70 (#45) and the battery positive terminal. Check for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
The resistance must be infinite.
Remedy as necessary.

Other information
- To access and replace the control module see SRS control module Removal and Replacement
- To access and replace the seat belt buckle, see Seat belt buckle Seat Belt Buckle
- For information about signals, see Signal specification Signal Description. Supplementary Restraint System (SRS)
- To connect the breakout box, see Connecting the breakout box Connecting The Breakout Box.









Was a fault detected?

Yes - Verification

No - Checking the component

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Checking the connector and cable








- Ignition on
- Disconnect the seat belt buckle connector
- Disconnect the control module connector.
Measure the resistance between seat belt buckle connector terminal #1 and control module connector terminal #73 (#48). Check for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
The resistance must be approximately 0 ohms. If not there is an open-circuit.
Remedy as necessary.

Other information
- To access and replace the control module see SRS control module Removal and Replacement
- To access and replace the seat belt buckle, see Seat belt buckle Seat Belt Buckle
- For information about signals, see Signal specification Signal Description. Supplementary Restraint System (SRS)
- To connect the breakout box, see Connecting the breakout box Connecting The Breakout Box.









Continue - Verification

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Checking the component




- Ignition off.
Try a new seat belt buckle if no faults were detected.

Other information
- To access and replace the seat belt buckle, see Seat belt buckle Seat Belt Buckle.





Continue - Verification

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Verification




Verification

Hint: After carrying out the repair, check that the fault has been remedied.




- Ignition off
- Disconnect the battery negative lead
- Reinstall the connectors, components etc.
- Ignition on
- Connect the battery negative lead.

Warning! There must not be anyone inside the passenger compartment when the battery is connected.

- Read off diagnostic trouble codes (DTCs).
The fault is no longer present if the status of the diagnostic trouble code (DTC) has changed to intermittent.





Does the status change?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFICATION FAILED - Fault-tracing information

VERIFIED - FAULT FOUND

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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 the power supply

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