Chassis, generic

C0920 Suspension Control Module Internal Fault

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C0920 is not found in any accessible list or bulletin. The title describes a suspension control unit that fails its own checks. GM names such a fault C0550 Electronic Control Unit, as the 2011 Saab 9-5 pages show: the self-test runs at power-up and needs only supply and ground, the module ignores further inputs, and it should only be replaced if the code is present as current and history entry; a history entry clears after 50 clean ignition cycles. Not every module swap is an internal fault: GM's PI0954 had 2010 LaCrosse suspension modules replaced because they did not accept service accelerometers, and Stellantis warns against replacing the damping module for stored codes. Audi logs C129700 for a limiting fault inside its roll stabiliser units.

Likely causes

Internal hardware or memory fault confirmed as current and history code
Poor supply or ground at the module triggering self-test failures
Software or parts incompatibility (GM PI0954, Audi 2067804/3)

Symptoms

  • Suspension service message, adaptive damping or levelling off
  • Other suspension codes may be stored alongside

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,600
Time0.5–3 h

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

Parts involved

suspension control module

Related codes

C0850C0851C0852C0853C0870C0915

References: saabwisonline.com, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.