Summary
C0265 means the Electronic Brake Control Module (EBCM) has detected a fault in its main power relay circuit. The EBCM relay supplies power to the ABS solenoid valves and pump motor. When this relay circuit fails, the EBCM cannot operate any of its hydraulic components, so ABS, traction control, and stability control are all disabled. The most common cause is a failed EBCM relay (35%), followed by internal EBCM circuit board failure (30%) and wiring or ground problems (20%). This code is especially common on GM vehicles from the mid-2000s.
Severity: High — ABS and all electronic brake systems are disabled
Safe to drive: Yes, with caution — conventional brakes work but ABS is disabled
Repair cost: $100–$1,200 depending on cause
DIY difficulty: Moderate to Hard
What does C0265 mean?
The EBCM (also called the ABS module on many vehicles) is the brain of the anti-lock braking system. It has a main power relay that feeds voltage to the hydraulic solenoid valves and pump motor inside the ABS modulator. When the EBCM commands ABS activation, the relay must be energized to provide power. The module monitors this relay circuit — it checks that the relay responds to commands and that voltage is present on the output side when the relay is closed.
C0265 is set when the EBCM detects that the relay is not functioning correctly. This can mean the relay does not energize when commanded, does not de-energize when released, or the voltage on the relay output does not match expectations. Once the code is set, the EBCM shuts down all hydraulic functions because it cannot guarantee control of brake pressure.
This code is particularly well-known on GM trucks and SUVs (Silverado, Sierra, Tahoe, Yukon, Suburban) from 2003–2007, where EBCM circuit board solder joint cracking is a widespread issue. In these vehicles, the problem is often inside the EBCM itself rather than in the external relay or wiring.