Signal Too Low. Permanent Fault

Signal too low. Permanent fault

Function test
Check that the SRS indicator lamp lights.

Does the lamp light?

Yes - Checking the connector and cable

No - Checking the cable

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Checking the connector and cable








- Ignition off
- Disconnect the battery negative lead
- Disconnect the SRS control module.
- Ignition on
- Connect the battery negative lead.

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

Connect a voltmeter between control module terminal #54 (#29) and the chassis ground. Check for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
The voltage must be approximately 8 V.
If the value deviates, disconnect the combined instrument panel connector B. Check terminal #B11. Check for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check the cable between combined instrument panel terminal #B11 and the control module terminal #54 (#29). Check for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Remedy as necessary.

Other information:
- To access and replace the control module see SRS control module Removal and Replacement
- To access and replace the combined instrument panel, see Driver information module (DIM), installation/removal, component replacement Removal and Replacement
- To connect the breakout box to the SRS, see Connecting the breakout box Connecting The Breakout Box

- For information about signals, see Signal specification Signal Description. Supplementary Restraint System (SRS).













Continue - Verification

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Checking the cable








- Ignition off
- Disconnect the battery negative lead
- Disconnect the SRS control module.
- Ignition on
- Connect the battery negative lead.

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

Connect an ohmmeter between control module terminal #54 (#29) and chassis ground. Check for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
The cable must be repaired or replaced if there is a short-circuit to ground. Otherwise the fault is in the combined instrument panel.

Hint: Connect control module terminal #54 (#29) to the chassis ground. The wiring is intact if the lamp is unlit.

Remedy as necessary.

Other information:
- To access and replace the control module see SRS control module Removal and Replacement
- To access and replace the combined instrument panel, see Driver information module (DIM), installation/removal, component replacement Removal and Replacement
- To connect the breakout box to the SRS, see Connecting the breakout box Connecting The Breakout Box
- To connect the breakout box to the combined instrument panel, see
- For information about signals, see Signal specification Signal Description. Supplementary Restraint System (SRS).









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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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 - Function test

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