Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SAS diagnostic functions: Notes
General
The control unit has built-in diagnostics, Volvo Diagnostics, which continually monitor the unit and the input and output signals.
Diagnostic trouble codes
If the control unit detects a fault, it stores a diagnostic trouble code. If, for any reason, a fault disappears after the diagnostic trouble code has been permanently stored in the control unit, information about the trouble code still remains in the control unit.
Reading and erasing diagnostic trouble codes
Stored diagnostic trouble codes can be read from the control unit using this facility.
Diagnostic trouble codes may be erased but only after they have been read at least once.
Reading input and output signals
Status of control unit input and output signals can be continually read using this facility.
For more information about parameters, see Description of parameters (steering angle sensor) .
Reading the control unit identity
VIDA identifies control units by reading the number of codes from the control unit memory. The codes contain information on the control unit as follows:
- hardware component number (control units without software)
- software component number (control units without software)
- software component number
- diagnostic software component number
Use the Manual With the Right Hardware
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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.
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