Contact numbering (1–42) of the ABS control unit connector block
1. Before starting the inspection, check the fuses and replace any faulty ones. Then turn off the ignition and disconnect all electrical consumers (headlights, radio, fan, etc.).
2. Remove the upper engine cover (see subsection 2.1).
3. Pull out the connector lock and, pulling it up, disconnect the connector from the control unit.
4. To check the power supply circuit of the ABS hydraulic pump, connect a voltmeter with the ignition off (measurement limit not less than 20 V) to contacts 1 and 2 of the connector.
5. The voltmeter should show a voltage approximately equal to the battery voltage. Otherwise, check the wires from pin 1 to ground and from pin 2 to the fuse box.
6. To check the power supply circuit of the solenoid valves, connect a voltmeter with the ignition off (measurement limit not less than 20 V) to contacts 5 and 6 of the connector.
7. The voltmeter should show a voltage approximately equal to the battery voltage. Otherwise, check the wires from pin 5 to ground and from pin 6 to the fuse box.
8. To check the power supply circuit of the ABS control unit, connect a voltmeter with the ignition off (measurement limit not less than 20 V) to contacts 23 and 5 of the connector.
9. The voltmeter should show a voltage approximately equal to the battery voltage. Otherwise, check the wires from pin 5 to ground and from pin 6 to terminal 15.
10. To check the brake light switch, connect a voltmeter with the ignition off (measurement limit not less than 20 V) to contacts 5 and 32 of the connector.
11. The voltmeter should show less than 1 V. If the voltage is different, check the brake light switch, as well as the wires from terminal 5 to ground and from terminal 32 to the brake light switch.
(Data taken from an online portal: www.SKODABOOK.ru)
12. Then press the brake pedal. The voltmeter should show a voltage approximately equal to the battery voltage. Otherwise, check the corresponding fuse.
13. To check the ASR switch, connect a voltmeter with the ignition off (measurement limit not less than 20 V) to contacts 5 and 27 of the connector. Turn on the ignition and ASR. The voltmeter should show a voltage approximately equal to the battery voltage.
14. Then turn off the ASR. The voltmeter should show less than 1 V. If not, check the wires from pin 5 to ground and from pin 27 to the ASR switch, as well as the ASR switch itself.
Circuits connected to the connector contacts
| Contact number | Circuits connected to the connector contacts |
| 1 | To the ground of terminal "31" |
| 2 | From the "+" terminal of the battery |
| 5 | To the ground of terminal "31" |
| 6 | From the "+" terminal of the battery |
| 12 | To the left front wheel speed sensor |
| 13 | To the left rear wheel speed sensor |
| 14 | To the left rear wheel speed sensor |
| 15 | To the right front wheel speed sensor |
| 16 | To the right front wheel speed sensor |
| 23 | Power from pin "15" |
| 24 | For data transmission (CAN-H) |
| 27 | To the ASR switch |
| 28 | To the left front wheel speed sensor |
| 30 | To the right rear wheel speed sensor |
| 31 | To the right rear wheel speed sensor |
| 32 | To the brake light switch |
| 40 | For data transmission (CAN-L) |
Contacts not listed in the table are not used.