Summary
C0242 indicates that the Powertrain Control Module (PCM) has sent a signal to the ABS/traction control module indicating it cannot support traction control operations. This is not a fault in the ABS system itself — the problem originates in the engine management system. The most common cause is an engine-related fault code that disables TCS (40%), followed by a throttle control system issue (25%) and communication failure between the PCM and ABS module (20%). Traction control is disabled, but ABS and standard braking remain operational.
Severity: Moderate — traction control is disabled but brakes function normally
Safe to drive: Yes, with care — traction control is inactive but all other systems work
Repair cost: $100–$800 depending on cause
DIY difficulty: Moderate
What does C0242 mean?
Traction control works by coordinating two systems: the ABS module reduces brake pressure on spinning wheels, while the PCM reduces engine power by retarding ignition timing, cutting fuel injectors, or closing the throttle. Both systems must cooperate for effective traction control.
C0242 is set when the PCM tells the ABS module that it cannot perform its share of traction control duties. The PCM does this when it has detected an internal fault — typically a problem with the electronic throttle control, engine sensors, or communication bus — that would make engine torque reduction unreliable or unsafe.
This code is a secondary effect. The root cause is almost always an engine management issue, and there will typically be a powertrain DTC (P-code) stored in the PCM alongside C0242. Fixing the underlying engine fault usually resolves C0242 automatically without any work on the ABS system itself.