Chassis, generic

C0598 Brake System Control Module B Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C0598 is the same summary check for a second brake control module, B. Such a module is found where braking is split between two units: Bosch gives its integrated power brake a separate backup unit for automated driving, so the vehicle still stops if the main unit fails. A BWI patent describes such a backup unit with its own control unit, motor and pumps for the front axle, linked to the main unit over a private CAN line and taking over pedal boost in the fallback mode. C0598 reports that unit B fails its internal checks. No manufacturer documents C0598 publicly; Toyota's use of C0597 for control module A shows the lettering. Redundancy or assist is reduced while it is stored.

Likely causes

Software or calibration fault in brake module B
Power supply or ground problem of module B
Internal hardware fault of module B
Fault on the link between the two brake modules

Symptoms

  • Brake system warning message
  • Driver assistance or automated driving functions unavailable
  • Reduced brake assist if the module handles boosting

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–3,000
Time0.5–4 h

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

Parts involved

bscm bbrake system control module

Related codes

C0597C0563C0599

References: bosch-mobility.com, patents.google.com, bosch-mobility.com, static.nhtsa.gov.