2012 Mercedes-Benz Sprinter Service & Repair Manual

2012 MERCEDES AND DODGE SPRINTER

2008 BRAKES ABS - Service Information - Sprinter BRAKES - ABS - SERVICE INFORMATION SPECIFICATIONS TORQUE CHART TORQUE ELECTRICAL DESCRIPTION WHEEL SPEED SENSOR DESCRIPTION N.m Ft. Lbs. In. Lbs. Brake Lines To Hydraulic unit 14 10 124 Dynamics Sensor 6 - 53 Hydraulic Control Unit (HCU) Initial torque 2 - 18 Hydraulic Control Unit (HCU) Final torque 3 - 26 Wheel Speed Sensor Front 8 - 71 Wheel Speed Sensor Rear 8 - 71 2008 BRAKES ABS - Service Information - Sprinter 2008 BRAKES ABS - Service Information - Sprinter

Fig. 1: Wheel Speed Sensor, Nut And Knuckle Courtesy of CHRYSLER LLC The ABS brake system uses 4 wheel speed sensors. A sensor (1) is mounted to each front knuckle (3) in the front. Fig. 2: Rear WSS Sensor Courtesy of CHRYSLER LLC A rear sensor (2) is mounted to each rear support plate. OPERATION SENSOR- WHEEL SPEED-ABS-FRONT Fig. 3: Front Wheel Speed Sensor Components Courtesy of CHRYSLER LLC The Wheel Speed Sensor consists of a magnet (1) surrounded by windings from a single strand of wire (5). The 2008 BRAKES ABS - Service Information - Sprinter

induction is created when a toothed sensor ring (exciter ring or tone wheel) (4) passes the stationary magnetic WSS. When the ring gear is rotated, the exciter ring (4) passes the tip of the WSS. As the exciter ring tooth approaches the tip of the WSS, the magnetic lines of force expand, causing the magnetic field to cut across the sensor's windings (5). This, in turn causes current to flow through the WSS circuit in one direction. When the exciter ring tooth moves away from the sensor tip, the magnetic lines of force collapse cutting the winding in the opposite direction. This causes the current to flow in the opposite direction. Every time a tooth of the exciter ring passes the tip of the WSS, an AC signal is generated current. Each AC signal (positive to negative signal or squarewave) is interpreted by the ABM. It then compares the frequency of the sinewave to a time value to calculate vehicle speed. The ABM continues to monitor the frequency to determine a deceleration rate that would indicate a possible wheel-locking tendency. The signal strength of any magnetic induction sensor is directly affected by: Magnetic field strength; the stronger the magnetic field, the stronger the signal Number of windings in the sensor; more windings provide a stronger signal Exciter ring speed; the faster the exciter ring/tone wheel rotates, the stronger the signal will be Distance (3) "air gap" between the exciter ring teeth and WSS; the closer the WSS is to the exciter ring/tone wheel, the stronger the signal will be. The WSS is not adjustable. A clearance specification has been established for manufacturing tolerances. If the clearance is not within these specifications, then either the WSS or other components may be damaged. The clearance between the WSS and the exciter ring is 0.005 - 0.050 in. The assembly plant performs a "Rolls Test" on every vehicle that leaves the assembly plant. One of the test performed is a test of the WSS. To properly test the sensor, the assembly plant connects test equipment to the Data Link Connector (DLC). This connector is located to the right of the steering column and attached to the lower portion of the instrument panel. The rolls test terminal is spliced to the WSS circuit. The vehicle is then driven on a set of rollers and the WSS output is monitored for proper operation. FRONT WHEEL SPEED SENSOR REMOVAL FRONT WHEEL SPEED SENSOR 2008 BRAKES ABS - Service Information - Sprinter

Fig. 4: Wheel Speed Sensor, Nut And Knuckle Courtesy of CHRYSLER LLC 1. Raise and support the vehicle. 2. Remove the front wheels. 3. Remove the wheel speed sensor nut (2). 4. Remove the wheel speed sensor (1) from the knuckle (3). INSTALLATION FRONT WHEEL SPEED SENSOR Fig. 5: Wheel Speed Sensor, Nut And Knuckle Courtesy of CHRYSLER LLC 1. Install the wheel speed sensor (1) all the way into the knuckle (3). Tighten the bolt (2) to 8 N.m (71in.lbs.). 2008 BRAKES ABS - Service Information - Sprinter

3. Lower the vehicle. REAR WHEEL SPEED SENSOR REMOVAL REAR WHEEL SPEED SENSOR - SINGLE REAR WHEEL (SRW) Fig. 6: Rear WSS Sensor Courtesy of CHRYSLER LLC 1. Raise and support the vehicle. 2. Remove the wheel speed sensor bolt (1) from the axle tube (4). 3. Remove the wheel speed sensor (2). 4. Remove the sensor wire from the tie strap (3). 5. Disconnect the sensor electrical connector. WHEEL SPEED SENSOR - DUAL REAR WHEEL (DRW) 2008 BRAKES ABS - Service Information - Sprinter

Fig. 7: Wheel Speed Sensor - Dual Rear Wheel Courtesy of CHRYSLER LLC 1. Raise and support the vehicle. 2. Remove the wheel speed sensor bolt (1) from the axle tube. 3. Remove the wheel speed sensor (2). 4. disconnect the electrical connector. 5. Remove the sensor wire from the tie strap. INSTALLATION REAR WHEEL SPEED SENSOR - SINGLE REAR WHEEL (SRW) Fig. 8: Rear WSS Sensor Courtesy of CHRYSLER LLC 1. Install the wheel speed sensor (2) in the axle tube (4) and tighten the bolt (1). Tighten to 8 N.m 2008 BRAKES ABS - Service Information - Sprinter

2. Install the tie straps (3) and the wire into the routing clips. 3. Reconnect the sensor electrical connector. 4. Lower the vehicle. REAR WHEEL SPEED SENSOR - DUAL REAR WHEEL (DRW) Fig. 9: Wheel Speed Sensor - Dual Rear Wheel Courtesy of CHRYSLER LLC 1. Install the wheel speed sensor (2) in the axle tube and tighten the bolt (1). Tighten to 8 N.m (71in.lbs.). 2. Install the tie straps) and the wire into the routing clips. 3. Reconnect the sensor electrical connector. 4. Lower the vehicle. TONE WHEEL REMOVAL TONE WHEEL NOTE: The tone wheel for single rear wheel (SRW) is integrated into the wheel hub/bearing assembly and not serviced separately. 2008 BRAKES ABS - Service Information - Sprinter

Fig. 10: Tone Wheel Removal Courtesy of CHRYSLER LLC 1. Remove the hub/bearing assembly (DRW) (3). Refer to REMOVAL . 2. Insert a hooked prybar (1) between the hub/bearing and the inside of the tone wheel and pry upwards slightly and work your way around the tone wheel until the wheel is loose. 3. Remove the tone wheel (2). INSTALLATION TONE WHEEL 1 - HOOKED PRYBAR 2 - TONE WHEEL 3 - HUB/BEARING ASSEMBLY 2008 BRAKES ABS - Service Information - Sprinter

1. Install the tone wheel to the hub/bearing with a thin bead of silicone around the tone wheel. 2. Tap the tone wheel down with a soft hammer until seated. 3. Install the hub/bearing (DRW). Refer to INSTALLATION . STEERING ANGLE SENSOR DESCRIPTION STEERING ANGLE SENSOR Fig. 11: Steering Angle Sensor Courtesy of CHRYSLER LLC Internal and integral to the clockspring are the Steering Control Module (SCM) (also known as the steering column module/MRM) and the Steering Angle Sensor (SAS). The clockspring (2) must be replaced for a steering angle sensor failure. REMOVAL STEERING ANGLE SENSOR 2008 BRAKES ABS - Service Information - Sprinter

2012 Mercedes-Benz Sprinter Service & Repair Manual

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