C0061

C0061 means the ABS Solenoid Valve Relay Circuit is reporting Open — the relay that supplies battery voltage to the ABS solenoid valve pack inside the modulator is either electrically open (relay coil burned out, harness broken, fuse blown) or commanded open by the ABS module because the module detected a fault elsewhere and intentionally killed valve power as a safety fallback. When this relay is open, the ABS function is disabled (you'll have an ABS warning lamp) but base hydraulic brakes still work normally — the pedal feels normal but the ABS won't pulse during a panic stop. Diagnostic order, cheapest first: (1) Check the ABS maxi-fuse in the underhood fuse box (usually a 40A or 60A maxi for the valve pack power supply, separate from the 5-20A logic fuse for the ABS module itself); a popped maxi means a hard short somewhere in the valve solenoids that needs investigation before just replacing the fuse. (2) Power-and-ground test at the relay socket: with key on, you should see 12V on the relay coil's +12V pin and on the load side's input pin; ground continuity on the coil's ground pin (or PWM command from the ABS module on modern systems that ground-side switch the relay). (3) Pull the relay and ohm the coil — typical ABS solenoid valve relay coil resistance is 60-120 ohms; open is infinite, shorted is near 0. (4) If the relay is good, measure resistance of each individual solenoid valve at the modulator connector — typical inlet/outlet solenoid resistance is 3-8 ohms; a shorted solenoid pulls the relay's load side down and either pops the fuse or makes the ABS module command the relay off as protection. (5) Only after testing relay and solenoids should you suspect the ABS module's internal relay-driver circuit. A clean $15 relay swap and a $5 fuse fix this 70% of the time on older vehicles; don't quote a $1,200 modulator replacement before testing.

Vehicle-specific patterns: 1999-2007 GM full-size trucks/SUVs with the Kelsey-Hayes 325 EBCM are the textbook C0061 case in North American shops — the relay driver inside the EBCM fails as part of the same internal solder-fracture pattern that produces C0035/C0050, so all three codes often appear together, and bench-rebuilding the EBCM for around $200 fixes all of them simultaneously vs. $1,200 for a new module. 2000-2005 Chevy Cavalier / Pontiac Sunfire with the Delphi ABS-VI system throws C0061 from the integrated relay package failing inside the modulator assembly. 2006-2011 Honda Civic / Accord with the VSA modulator throws C0061 alongside U0121 when the VSA control unit fails (covered under Honda recall on certain VINs). 2003-2010 Ford F-150 / Explorer / Mountaineer throws C0061 from corroded battery-side terminal at the underhood relay/fuse box, particularly on salt-belt vehicles where the lead-acid corrosion creeps into the underhood box; clean the terminal and replace the relay socket if it's green. Estimated repair: $5 (replacing a popped fuse) to $1,200 (full ABS modulator + EBCM assembly with programming).