Chassis, generic

C0225 ABS Valve Relay Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C0225 is missing from the accessible J2012 lists. GM does use the number: its terminal-test bulletin PIP5094 for 2014 and older cars and light trucks lists it among the chassis codes, and AA1Car's table of GM ABS codes gives it as Left Front Wheel Speed Sensor Circuit Open, not as a valve relay fault. No maker on record documents a valve relay meaning. For the relay named in the title, a Hella/Lucas patent explains the job: one relay contact supplies all ABS valves, and the module checks both coil current and switched voltage, opening the relay on a fault so the valves return to rest. On a GM vehicle with C0225, the left front sensor circuit deserves the first look; HELLA notes that only passive sensors can be checked by resistance.

Likely causes

On GM vehicles open left front wheel speed sensor or its wiring
Burnt or sticking valve relay contact
Blown fuse or poor ground in the relay circuit

Symptoms

  • ABS warning lamp on, ABS disabled
  • Traction control or speedometer function affected on some vehicles

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–600
Time0.3–2 h

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

Parts involved

abs valve relayabs control modulerelay wiring

Related codes

C0121C0220C0035

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