Signal Description, Control Unit For The Steering Wheel Angle Sensor (SAS)
The values in the table represent the values between the connections shown in column 1 and #A40 (ground), unless otherwise stated in brackets.
NOTE:
It is important that the test box is connected and the ground points checked before testing begins.
| U= | DC voltage (V) | Ubat = | battery voltage (V) | |
| I = | amperage (A) | Ulow = | voltage close to 0 V |
| Test box connection | Control unit connection | Signal type | Ignition on | Other |
| #A25 | #1 | 15 supply (voltage supply from the ignition lock) | U(Ubat | - |
| #A26 | #2 | Voltage supply to steering wheel angle sensor | U(Ubat | 15 supply through control unit |
| #A27 | #3 | Steering wheel angle signal A | <0.25 V (low) >0.75 V (high) I(1 mA |
Steering wheel angle signal The coding wheel in the steering wheel angle sensor is perforated with a special code template. Two circuits, each with 4 LEDs and 4 receptors, read the coding wheel and send a pulsed signal containing information about the position of the steering wheel. |
| #A28 | #4 | Steering wheel angle signal B | <0.25 V (low) >0.75 V (high) I(1 mA |
Steering wheel angle sensor signal For more information, see steering wheel angle signal A. |
| #A29 | #5 | Steering wheel position signal R1 | <0.25 V (low) >0.75 V (high) I(1 mA |
Sector identifier For more information, see steering wheel angle signal A. |
| #A30 | #6 | Control unit communication wire (CAN H) | U=2-3 V | CAN High speed, Multiplex wire. |
| #A31 | #7 | Signal and power ground for steering wheel angle sensor | - | - |
| #A32 | #8 | LED circuit 2 signal | - | LED circuit 2 current test |
| #A33 | #9 | LED circuit 1 signal | - | LED circuit 1 current test |
| #A34 | #10 | Steering wheel angle signal IX | <0.25 V (low) >0.75 V (high) I(1 mA |
Steering wheel angle sensor signal For more information, see steering wheel angle signal A. |
| #A35 | #11 | Steering wheel angle signal IY | <0.25V (low) >0.75 V (high) I(1 mA |
Steering wheel angle sensor signal For more information, see steering wheel angle signal A. |
| #A36 | #12 | Steering wheel position R2 signal | <0.25 V (low) >0.75 V (high) I(1 mA |
Sector identifier For more information, see signal A. |
| #A37 | #13 | Steering wheel position R3 signal | <0.25 V (low) >0.75 V (high) I(1 mA |
Sector identifier For more information, see signal A. |
| #A38 | #14 | Steering wheel position R4 signal | <0.25 V (low) >0.75 V (high) I(1 mA |
Sector identifier For more information, see signal A. |
| #A39 | #15 | Control unit communication wire (CAN L) | U=2-3 V | CAN Low speed, Multiplex wire. |
| #A40 | #16 | Signal and power ground (measured against the battery negative terminal). | U(Ulow | - |