Scheme 1
Scheme 2
Scheme 3
Scheme 4
- Ignition off
- the control module disconnected
- Switch off all equipment that takes power from the battery (courtesy lighting, radio etc). Connect an ohmmeter between terminal #16 on the breakout box and the battery negative terminal. To connect the breakout box, see «CONNECTING THE BREAKOUT BOX»(ref-476731-S03025038282012060500000).
The ohmmeter should read approximately 0 ohms.
- OK OKAY: Troubleshooting has been completed.
- NOT OK Refer to «CHECKING FOR OPEN-CIRCUITS, CONTACT RESISTANCE AND OXIDATION»(ref-476731-S10225149032012060500000)
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 |