P23C6: Engine Coolant Bypass Valve C Control Circuit Driver Current or Temperature Too High

What it means

The driver stage of the coolant bypass valve C reports excessive current draw or thermal protection trip - typically a sticking valve drawing too much motor current.

At a glance

• Usually lights the check-engine light

How it works

The control module drives coolant bypass valve C and monitors the current and temperature of the valve's driver circuit. This code sets when the driver draws excessive current or becomes hot enough to trigger protection, often because the valve is binding or its actuator circuit is shorted.

Common causes

Most likely first.

1. Valve C motor or actuator drawing excessive current
2. Coolant bypass valve C sticking or binding
3. Short or high resistance in the actuator wiring or connector
4. Fault in the valve driver or control module

Symptoms

• Check engine light
• Possible abnormal engine temperature or weak cabin heat

How to diagnose it

1. Review freeze-frame data and related valve codes to see when the valve C driver overheated or drew excess current.
2. Check live commanded and reported valve C position, if available, and note whether the valve fails to move or coolant temperature behaves abnormally.
3. Inspect valve C and its connector for coolant contamination, corrosion, heat damage, or harness chafing.
4. With the system safely isolated, check the actuator wiring for shorts or abnormal resistance against the manufacturer's specification.
5. Test whether valve C moves freely and whether the actuator draws current within the manufacturer's specification during a commanded test.
6. If the valve and wiring pass, test the control module's valve C driver according to the manufacturer's procedure.

Common fixes

• Repair chafed or shorted valve C actuator wiring and damaged connector terminals.
• Replace coolant bypass valve C if it binds or its actuator draws excessive current.
• Correct contamination or mechanical obstruction that is causing valve C to stick, if applicable.
• Repair or replace the valve driver or control module if testing confirms an internal driver fault.

Can I keep driving?

Drive only if engine temperature remains stable, and monitor the temperature gauge closely; stop if the engine overheats. A stuck or disabled valve can disrupt coolant flow and lead to overheating or loss of cabin heat.