Chassis, generic

C0265 EBCM Relay Circuit

Check engine lightUsually off

EmissionsNot relevant

Drive cycleNot required

Limp modePossible

C0265 does not appear in the published J2012 lists; it belongs to GM's numbering. PIP5094, GM's terminal-check bulletin for 2014 and older vehicles, includes it, and in AA1Car's listing of GM ABS faults it is EBCM Relay Circuit, matching the title. GM does not publish the setting rule for this number. The task of such a relay is described in a Hella/Lucas patent: one contact switches battery voltage to all ABS valves, and the module watches both coil current and the voltage behind the contact. If either is wrong, the relay is dropped, the valves lose power, and the car brakes conventionally without ABS while the warning lamp is lit. Check fuses, relay contacts and the module ground before replacing the brake module.

Likely causes

Blown fuse or poor battery feed to the relay

Burnt or sticking relay contacts (internal relay in later modules)

Poor ground at the brake control module

Symptoms

ABS warning lamp on, ABS disabled
Traction control unavailable on equipped vehicles

Repair estimate

DifficultyMediumDIY possible

Parts and labour€20–900

Time0.3–2.5 h

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

Parts involved

ebcm relayebcm modulepower supply wiring

Related codes

C0266 C0121 C0225

References: static.nhtsa.gov, aa1car.com, patents.google.com.