Chassis, generic

C0523 Multi-axis Acceleration Sensor Module B Intermittent/Erratic

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

Module B sends values that jump or drop out now and then. No manufacturer publishes C0523, so limits and the identity of module B stay open. GM bulletins show that a separate multi-axis module is a networked unit of its own: on 2013 to 2014 Malibu, LaCrosse and Regal it logs U0121 in history at key-up because the brake module answers late, which GM calls normal, and on 2018 to 2020 Equinox and Terrain U0125 for a lost module is cured by brake controller software. Such communication codes are separate from C0523, which concerns erratic content. Bosch's SMI810 sends 16-bit SafeSPI frames, so contact faults appear as sporadic bad samples. Warnings may come and go.

Likely causes

Loose or corroded connector or ground at module B
Supply dips from a weak battery or poor connections
Sporadic internal fault in module B

Symptoms

  • Assistance or ESC warning comes and goes
  • Code stored in history without current fault
  • Jumping values from module B in live data

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–1,000
Time0.5–3 h

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

Parts involved

multi axis accel module b

Related codes

C051EC0521C0522C0524C0525U0125

References: static.nhtsa.gov, static.nhtsa.gov, bosch-semiconductors.com.