Faulty Signal

2007 Volvo XC90 AWD V8-4.4L VIN 85 B8444SSECTION Faulty Signal





Faulty signal

Checking the component
The infotainment module (ICM) has registered that the Accessory USB unit (AUU) is invalid according to the list stored in the central electronic module (CEM).
The cause of the fault is probably that no software has been downloaded or that software downloading has failed after replacing Accessory USB unit (AUU).

Hint: When downloading software after replacing a control module, the serial number of the control module is stored in the central electronic module (CEM). This is so that the security on MOST function can approve the control module in the MOST network in the car.

If the fault persists after software download, try replacing the Accessory USB unit (AUU).
Remedy as necessary.

Other information
- Universal bus module (USB), L.H.D Universal Bus Module (USB)





Continue - Verification

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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 component

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Verification

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

- Ignition off.
- Reinstall the connectors, components etc.
- Ignition on.
Check function of the Accessory USB Unit (AUU).

Is the system working?

Yes - FAULT FOUND

No - Fault-tracing information

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RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.