Basic concepts
Before you read this section, you need to understand some concepts. Without them, diagnostic testing may be difficult.
Basic electrical circuits: you need to know the basic theoretical positions of electricity and be aware of the meaning of voltage, current (A) and resistance (Ohm). You also need to know what happens in the circuit if an open or short is detected. It is necessary to correctly read and understand the wiring diagram.
Using Circuit Testing Tools: You need to know how to properly use the digital multimeter, as well as other measuring instruments. You need to be able to measure voltage, resistance, current, have an idea how to bypass parts in order to check the circuit with a jumper wire.
ABS system components
ABS modification DBC7 consists of a hydraulic braking system with anti-lock components. A typical braking system includes:
- vacuum booster;
- master brake cylinder;
- front disc brakes;
- rear drum brakes;
- connecting hydraulic brake pipes and hoses;
- brake fluid level sensor;
- BRAKE indicator. The ABS system includes:
- hydraulic device;
- electronic brake control module (EMUT);
- fuse;
- four wheel speed sensors (one for each wheel);
- electrical wiring;
- ABS indicator;
- indicator (connected to the parking brake lamp);
- DDRP system (separate dynamic metered distribution to the rear wheels);
- rear drum brakes.
The hydraulic device with EMUT is located between the expansion tank and the heat-insulating wall on the left side of the car.
Specifications
| ABS mode | 4 channels 4 sensors |
| ABS main relay operating voltage | 9-16V |
| Front wheel speed sensor | - |
| Resistance | 988-1.208 ohm |
| air gap | 0.5-1.2mm |
| Rear wheel speed sensor | - |
| Resistance | 2.295-2.500 ohms |
| air gap | 0.6-1.2 mm |
| Ring of Speed | - |
| Outside diameter (front) | 83.72 mm |
| Outside diameter (rear) | 77 mm |
| Inner diameter (front) | 73.75 mm |
| Inner diameter (rear) | 67 |
| Number of teeth of the speed ring (anterior) | 47 |
| Number of teeth of the speed ring (rear) | 34 |
| brake oil | - |
| Type | DOT-3, DOT-4 |
| Volume | 0.5 l |
Tightening torques for threaded connections
| Nut of fastening of a brake line (hydraulic unit) | 16 Nm |
| ABS mounting bracket bolt | 22 Nm |
| Front Wheel Speed Sensor Bolt | 9 Nm |
| Rear Wheel Speed Sensor Bolt | 9 Nm |
The main hydraulic device consists of:
- hydraulic control valves;
- two solenoid valves for each wheel;
- hydraulic pump;
- two drives;
- two dampers.
The hydraulic device controls the hydraulic pressure supplied to the front and rear wheel cylinders by varying the hydraulic pressure to prevent the wheels from locking when braking.
ABS block diagram
1. Hydraulic modulator; 2 Bracket; 3. Front wheel speed sensor; 4. Rear wheel speed sensor.
Placement of ABS elements
1. Hydraulic modulator block; 2. Bracket for fastening the hydraulic modulator unit; 3. Front wheel speed sensor; 4. Rear wheel speed sensor.