Chassis, generic

C051C Multi-axis Acceleration Sensor Module A Range/Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

Module A delivers yaw rate and accelerations along several axes, but at least one channel sits outside what the vehicle's motion allows, for example a turn rate while parked or a lateral g that does not fit speed and steering. No manufacturer documents C051C publicly, so exact limits are unknown. Patents show why such checks matter: in a Kelsey-Hayes (now ZF) filing a sensor tilted by 5 degrees reports about 8.7 deg/s of yaw during a hard pitch, while stability control typically reacts at 3 to 7 deg/s; an Autoliv patent tracks slowly creeping offsets with a moving average. Unlike the calibration and correlation codes, here the reading itself is implausible. Stability control usually switches off with its warning lamp lit.

Likely causes

Module A loose, tilted or mounted on a deformed bracket
Internal offset of the inertial sensor drifted beyond tolerance
Defective sensing element inside module A
Wrong module variant fitted or installed in the wrong orientation

Symptoms

  • ESC or traction control warning lamp on
  • Stability control unavailable or intervening without reason
  • Yaw rate or acceleration not zero at standstill (scan tool)

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–900
Time0.5–2.5 h

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

Parts involved

multi axis accel module a

Related codes

C051DC051EC051FC0520C0521C006A

References: patents.google.com, patents.google.com, bosch-mobility.com.