C0265 — EBCM Motor Relay Circuit (GM)

The Kelsey-Hayes 325 EBCM on GM’s 1999-2008 full-size trucks and SUVs — Silverado, Sierra, Tahoe, Suburban, Yukon, Avalanche, and their vans — fails in one famous way: the solder joints around its internal pump-motor relay crack with age and heat cycling. When the module commands the relay and the cracked joint opens under load, C0265 is stored and the ABS light comes on. Early on it is intermittent — the light comes and goes with temperature, because the crack opens and closes as the board expands — and then one day it stays.

Because the failure is so specific and so common, this repair became a category of its own in the independent trade years ago. It is genuinely good news as module failures go: the fault is joints, not silicon, the module unbolts from the hydraulic block right on the truck, and the brake hydraulics never get opened — no bleed, no special tools, about fifteen minutes with a Torx driver at the frame rail.

Many of these trucks also suffer a second, different fault that owners lump together with C0265: the ABS grabbing or buzzing at walking speed on a smooth stop. That behavior is usually the front wheel-speed sensors — rust jacking under the sensor mounts corrupts the air gap, the module sees a phantom wheel-lock at 3 mph, and fires the ABS. That is an on-car fix (clean the mounts, replace the sensor), not a module repair.

The two faults coexist on a lot of trucks, so be precise about which you have: C0265 stored with the ABS light on is the module’s internal relay — our job. Low-speed activation with C0035/C0040-series corner codes is the hubs — your job or your shop’s. Plenty of trucks need both, and doing only one leaves the other symptom standing.

Your module is photographed at intake, opened on a grounded ESD workstation, and inspected under magnification before anything is powered. ABS controllers fail in predictable places — the high-current driver stages, the processor, and the solder joints that carry years of engine-bay heat cycling — so the diagnosis starts where the failures live.

The repair is board-level: the failed component is removed and replaced, the surrounding joints are reworked, and the board is cleaned of flux before reassembly and resealing. Because it is your original module, the VIN, coding, and calibration never leave the unit — there is nothing to program at the dealer afterward.

Before it ships back, the module is verified on the bench: powered from a regulated supply, communication confirmed over OBD, the fault code cleared and re-read to confirm it stays gone, and wheel-speed inputs exercised in live data. The repair carries our 6-month warranty, and typical bench time is about a day — most of the calendar time on these jobs is shipping in both directions.