Internal failure of the brake system control module, such as a faulty processor, memory chip, or output driver; Low or unstable system voltage reaching the module, often from a weak battery or failing alternator; Corroded, loose, or damaged ground connections at the module or chassis; Wiring harness damage or poor pin fit in the module connector causing intermittent circuit faults; Water intrusion into the module housing or connector, common when the unit is mounted low in the engine bay; A failed self-test caused by a related sensor or actuator fault that the module interprets as its own performance error; Software or calibration corruption in the module requiring reflash or replacement

DTC codes / C05xx · Brakes, steering and suspension / C0598

C0598Brake System Control Module B Performance

Q: What does code C0598 mean?

Brake System Control Module B Performance. C0598 means the brake system control module has detected an internal performance fault in its 'B' circuit or processing channel, so it cannot trust its own brake control calculations. The module sets this code when its self-test routines find that a redundant processor, memory area, or output driver is not responding within the expected limits.

C0598 means the brake system control module has detected an internal performance fault in its 'B' circuit or processing channel, so it cannot trust its own brake control calculations. The module sets this code when its self-test routines find that a redundant processor, memory area, or output driver is not responding within the expected limits.

SystemChassis

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaBrakes, steering and suspension

Symptoms you may notice

Anti-lock braking system (ABS) warning light illuminated steadily on the dashboard
Traction control and stability control warning lights also on because those functions rely on the same module
ABS disabled, with wheel lockup possible during hard braking on slippery surfaces
Electronic brake force distribution may default to a fixed front/rear split, changing pedal feel
Often no symptoms besides the warning light, with normal braking in everyday driving
Intermittent warning light that comes and goes with temperature or vibration

Common causes, most likely first

Internal failure of the brake system control module, such as a faulty processor, memory chip, or output driver
Low or unstable system voltage reaching the module, often from a weak battery or failing alternator
Corroded, loose, or damaged ground connections at the module or chassis
Wiring harness damage or poor pin fit in the module connector causing intermittent circuit faults
Water intrusion into the module housing or connector, common when the unit is mounted low in the engine bay
A failed self-test caused by a related sensor or actuator fault that the module interprets as its own performance error
Software or calibration corruption in the module requiring reflash or replacement

How to diagnose and fix it

Scan all modules and record every stored and pending code before clearing anything, since companion codes point to the real root cause
Test battery voltage at rest and while cranking, and check charging voltage at idle to rule out low-voltage faults
Inspect and clean the module ground points and connector pins, looking for corrosion, water intrusion, or loose terminals
Perform a wiggle test on the module harness while watching live data for dropouts or intermittent communication
Follow the manufacturer's pinpoint test for C0598, which usually checks power, ground, and communication circuits to the module
If circuits test good, reflash or reprogram the module with the latest calibration before condemning it
Replace the brake system control module and perform any required coding, calibration, or adaptation procedure

Why this code is rarely just a bad module

A weak battery or failing alternator is a very common trigger for C0598 because the module's self-test fails when supply voltage dips during cranking or under load.
Technicians often replace the brake control module only to find the real fault was a corroded ground or chafed harness, so circuit checks must come first.
Companion codes in the ABS module, such as wheel speed sensor or pump motor codes, can cause the module to set a performance code for itself even when the module is healthy.
Water intrusion into a module mounted low in the engine bay or under the master cylinder is a frequent hidden cause, especially after winter driving or a car wash.
After module replacement, many vehicles require calibration or coding of the new unit, and skipping that step leaves the warning light on and the code returning.

Can I keep driving with C0598?

The vehicle remains driveable with normal hydraulic brakes, but ABS and stability control are disabled, so avoid hard braking, slippery roads, and towing until the fault is repaired. If the pedal feel changes or the red brake warning light also comes on, stop driving and have the vehicle towed.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.