Signal Too High. Permanent Fault
Signal too high. Permanent fault
Checking the components
- Make a note of any radio code.
- Ignition off.
- Disconnect the battery negative lead.
- Disconnect connector from passenger air bag.
Warning! Never use an ohmmeter or any other charged measuring instrument on a disconnected, undeployed air bag module. There is a risk that the air bag could be deployed!
- Connect the special tool 919 4732 Test dummy 919 4732 Test Dummy to the passenger air bag connector.
Caution! The special tool must be checked and fault-free. If the tool is faulty, this will cause an incorrect display in the diagnosis and make fault localization harder.
- Ignition on.
- Connect the battery negative lead.
- Read the diagnostic trouble codes.
If a fault is found in the passenger air bag the status will now have changed to intermittent fault; test by replacing the passenger air bag and verify afterwards.
Additional information:
- To access/replace passenger air bag, see Removal and Replacement.
Has the status of the diagnostic trouble code changed?
Yes - Verification
No - Checking the wiring
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Checking the wiring
- Ignition off.
- Disconnect the special tool 919 4732 Test dummy 919 4732 Test Dummy.
- Ignition on.
Connect an oscilloscope between passenger air bag #1 and #2. The oscilloscope should now show a spiked pulse with a period time of approximately 500 ms and an offset of approximately 2 V.
If the value deviates, this means that there is a short circuit to the battery voltage in the wire, so the cable harness must be replaced.
Also test between ground and passenger air bag #2; the oscilloscope should show approximately 2 V.
Do the necessary corrective action.
Note! After this test, diagnostic trouble code SRS-222 is set. Ignore this code, which is set as a result of the test.
Additional information:
- To access/replace passenger air bag, see Removal and Replacement.
Select Continue when the fault has been rectified.
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 - Trouble-shooting information
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Trouble-shooting 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 components
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