C0085
Left Rear ABS Solenoid #2 Circuit Malfunction
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Code C0085 indicates a malfunction in the left rear ABS solenoid #2 circuit. The #2 solenoid is typically the dump valve, which releases brake pressure from the left rear wheel caliper during an ABS event. When the ABS system detects that the left rear wheel is about to lock up, this solenoid opens to reduce braking force and allow the wheel to regain traction.
When this code is stored, the ABS system disables itself as a safety precaution, and your traction control and stability control systems will also be turned off. Normal braking will still work, but you lose the safety net of anti-lock braking. Rear ABS solenoid failures can be particularly noticeable on rear-wheel-drive and all-wheel-drive vehicles during slippery conditions.
Have this inspected within the week, especially if you frequently drive in rain, snow, or on gravel roads where ABS is most needed. The technician will test the solenoid circuit with a multimeter and scan tool, checking for proper resistance values and command response. Since ABS solenoids are typically integrated into the hydraulic modulator, the entire unit often needs replacement rather than just the individual solenoid.
Severity
Symptoms
- •ABS warning light on dashboard
- •Left rear wheel locks during hard braking
- •Traction control light illuminated
- •Vehicle pulls to one side during ABS activation
- •Longer stopping distances in wet conditions
- •Stability control system disabled
Likely Causes
The left rear #2 solenoid (dump valve) within the ABS hydraulic modulator has failed electrically or is mechanically stuck, preventing proper brake pressure release during ABS events.
The wiring harness and connectors feeding the solenoid circuit are exposed to road splash and salt, making them susceptible to corrosion, especially on the rear circuits.
The internal driver transistor in the Electronic Brake Control Module that controls this specific solenoid can fail, causing the code to set.
Moisture-contaminated or degraded brake fluid can cause internal corrosion of the solenoid valve, leading to erratic operation and circuit faults.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Repair or replace damaged wiring and connectors in the ABS solenoid circuit
- Replace the ABS hydraulic modulator assembly
- Replace the EBCM if internal driver failure is confirmed
- Flush brake system with fresh DOT-specification fluid