Chassis, generic

C0405 Traction Control Active Too Long

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C0405 could not be found in any public source, including the public J2012 tables, GM's PIP5094 and NHTSA's bulletin index, and no maker publishes a time limit for a traction control intervention. So only the monitored function is outlined. Traction control brakes a spinning drive wheel and asks the engine for less torque; Bosch counts it among the functions of ESP. In the 2004 Saab 9-5 the return pump runs throughout every TCS or ESP braking event while the control valves raise, hold and lower pressure, and the function lamp lights only when braking and torque reduction act together. An intervention lasting far longer than expected suggests a false wheel speed or a stuck valve; how and when a system then reacts is maker specific.

Likely causes

Erratic wheel speed signal faking continuous wheel spin
Spare wheel or tires of different size on one axle
Hydraulic control valve sticking in the brake unit

Symptoms

  • Traction control lamp flashes for a long time or stays on
  • Engine power reduced and a wheel braked without reason
  • Hot or smelling brake on one wheel

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–800
Time0.5–3 h

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

Parts involved

abs control modulewheel speed sensors

Related codes

C0400C0401

References: saabwisonline.com, saabwisonline.com, bosch-mobility.com.