Defect Code 07

Defect Code 07:

Explanation:

No or faulty sensor signal from front left wheel sensor

Possible causes:

Short or break to ground or the signal line to/from the speed sensor

Different tyres on rear axle (different wheel circumferences)

Defective pulse wheel (corrosion, dirt, tooth damage)

Incorrect number of teeth on pulse wheel

Air gap (clearance) too large or too small

Wheel speed sensor defective or dirty

Troubleshooting:

Perform following checks and repair or renew defective components as necessary:

- Check tyres of correct tyre size on all four wheels

- Check wheel bearing play at all four wheels and renew bearings if necessary

Check pulse wheel (number of teeth 48, damage, corrosion, dirt build-up)

- Check air gap (clearance) (nominal value 0.05.. .0.9 mm)

- Check wheel speed sensors (mechanical damage, dirt build&up e.g. metal particles)

- Check wheel speed sensor line (mechanical damage e.g. pinched points)

- Check plug connections under the left rear seat (firm connection, corrosion, connection interchanged)

Switch off ignition and disconnect the ABS/ASC control unit. Perform following measurements and in the case of deviation renew defective components:

Resistance wire harness side Pin 8/26; nominal value: 650...1600 Ohm; move wires and plug connection (loose contact): if necessary detach plug connection and repeat resistance measurement to locate defect Perform dynamic speed signal test at Pin 8/26.

Ensure waves are uniform, if necessary, renew pulse wheel or wheel speed sensor.