Defect Code 07

Defect Code 07:

Explanation:

No or faulty sensor signal from front left wheel sensor

Possible cause:

Short or break to ground or the signal line to/from the speed sensor
Different tires on front 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 tires for correct tire 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 speed sensor wire (mechanical damage e.g. pinched parts)
- Check plug connections in left of engine compartment (firm connection, corrosion, connection interchanged)
- Check speed sensor (mechanical damage, dirt build-up, e.g. metal particles)

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

Static:

Resistance wire harness side Pin 48/50: Nominal value: 650... 1600 Ohm; move wires and plug connection (loose contact); If necessary detach plug connection and repeat resistance measurement to indicate defect. Perform dynamic speed signal test at Pin 48/50.

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