Chassis, generic

C05F0 Rear Drive Shaft Speed Sensor Circuit Low

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

The signal of the rear drive shaft speed sensor stays below its valid range, typically due to an open circuit, a short to ground or a missing sensor supply. The AWD module needs this speed to match a disconnected rear driveline to the wheels before a clutch closes; American Axle's patent feeds a pinion shaft speed sensor into exactly that synchronisation check. Audi lists the driveshaft speed sensor G970 among the parts tested in quattro ultra fault finding for C05ED00. Many such sensors are two-wire Hall ICs that toggle between two supply currents; Allegro's A19420 uses about 7 and 14 mA, so a current below the lower band, or none at all, cannot be a valid pulse. No manufacturer publishes C05F0 itself; C05F1 is the high counterpart.

Likely causes

Open sensor wire or loose connector
Signal or supply line shorted to ground
Failed Hall sensor IC

Symptoms

  • AWD warning, all-wheel drive not connected
  • Vehicle drives in front-wheel drive only

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–400
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

rear drive shaft speed sensor

Related codes

C05F1C05F3C05F4C05F2C05EE

References: patents.google.com, static.nhtsa.gov, allegromicro.com.