Diagnostic Functions

SAS DIAGNOSTIC FUNCTIONS

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 function.
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 function.

Description of parameters
Introduction / status

General
The steering wheel angle sensor module (SAS) must be initiated before values can be read off. Initiation is carried out by turning the steering wheel more than 5° in either direction.

Steering wheel angle
The value displays the steering wheel angle in degrees.
0° = Steering wheel in the straight forward position
1° to 500° = Steering wheel angle

Steering wheel movement speed
The value displays the steering wheel turning speed in °/second.
Measurement range: 0 - 255°/second

Steering direction
The value indicates in which direction the steering wheel is turned.
The values displayed are right or left.

Power supply
The value indicates battery voltage at the steering wheel angle sensor module (SAS).
Measurement range: 5 - 15 V

READING THE CONTROL UNIT IDENTITY
VADIS/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 P/N
- software P/N
- diagnostic software P/N