C0085 Code: Left Rear Wheel ABS Solenoid Valve 2 Circuit Failure

What the C0085 code means

The ABS module (EBCM) controls the anti-lock brakes and, on most modern vehicles, traction control and stability control too. When it detects a fault, it disables those functions and turns on the ABS and stability warning lights. The normal brakes keep working.

The ABS hydraulic unit has two valves for each wheel. Valve 2 is the outlet (release) valve: it lets fluid escape from the wheel to lower the pressure so the wheel does not lock. The C0085 code means the module detected an open circuit, a short or a resistance out of range in that valve.

The valves are inside the hydraulic unit, and their coils are usually part of the ABS module itself. That is why the fault is almost always fixed by repairing or replacing the module (sometimes only the electronics can be repaired), not the whole hydraulic unit.

Important: many C and B codes are not generic. The definition on this page is the most widespread one, used by General Motors and most generic scan tools, but on other makes the same number can mean something else. Always confirm the code text with a scan tool that reads the right module (ABS, body or airbag).

When several valve codes for different wheels show up at the same time, the valves are almost never the problem. That points to the module supply or its internal electronics. Check the battery, the fuses and the ground first, before you order a new module.

C0085 code symptoms

• ABS and stability control warning lights on.
• The ABS does not act.
• Several valve codes stored at the same time, which points to the module and not to individual valves.

Likely causes of the C0085 code

1. Valve coil inside the ABS module. The most common cause.
2. Internal connections of the module, such as cracked solder joints.
3. Module supply, meaning a fuse or a ground.
4. Hydraulic unit. Rarely.

How to diagnose the C0085 code step by step

1. Check the supply and grounds of the ABS module. Start with the battery, the fuses and the ground connections.
2. Read all the ABS codes. Several valve codes at once point to the module.
3. Command the valve with the scan tool if it supports that, and see whether it responds.

How to fix the C0085 code

• Repair or replace the ABS module.
• If it is replaced, program it and bleed the system with the scan tool following the manufacturer procedure.

Technical reference data

• Typical coil resistance: a few ohms.
• Valve 1 is the inlet (isolation) valve, and valve 2 is the outlet (release) valve.
• These values are approximate. Check the manufacturer data for your vehicle.

Brand-specific notes

Before you buy a new module, rule out low battery voltage, a blown fuse and a poor ground. They cost far less and they can set valve codes on their own.

C0085 on GM, Ford and Chrysler

On many GM, Ford and Chrysler vehicles there are companies that repair the electronics of the ABS module at a lower cost than a new one.

Frequently asked questions about C0085