A shorted or partially shorted refrigerant distribution valve solenoid winding, which draws more current than the driver expects.; Damaged or chafed wiring between the control module and the valve, allowing the control circuit to short to ground or to battery voltage.; Corroded or loose connector terminals at the valve or at the control module, raising resistance and heat in the driver circuit.; A failing control module driver stage that can no longer regulate current properly, often caused by repeated exposure to a shorted valve.; Internal valve mechanical binding that forces the solenoid to draw excessive current as it tries to move the spool.; Contamination or debris in the refrigerant circuit that restricts valve movement and increases solenoid load.; Extreme underhood temperatures or a missing heat shield that pushes the driver circuit beyond its thermal design limit.

DTC codes / P26xx · Computer and output circuits / P266F

P266FA/C Refrigerant Distribution Valve A Control Circuit Driver Current/Temperature Too High

P266F indicates that the powertrain control module has detected excessive current or temperature in the driver circuit for the A/C refrigerant distribution valve A, which is used to route refrigerant between the cabin evaporator and other cooling loops. The module monitors the control wire for current draw and calculates driver temperature, and it sets this code when either value exceeds a calibrated limit for a defined period.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaComputer and output circuits

Symptoms you may notice

The air conditioning may blow warm air on one side or from one vent while other outlets remain cold.
The A/C compressor clutch may cycle rapidly or refuse to engage at all.
A noticeable delay or complete loss of cooling after the engine is started.
The check engine light illuminates, sometimes accompanied by a flashing A/C button or climate control warning.
Often no symptoms besides the warning light, especially if the valve is stuck in a position that still provides acceptable cooling.
In some vehicles, the engine cooling fan may run continuously or the climate control panel may default to a fixed blend position.

Common causes, most likely first

A shorted or partially shorted refrigerant distribution valve solenoid winding, which draws more current than the driver expects.
Damaged or chafed wiring between the control module and the valve, allowing the control circuit to short to ground or to battery voltage.
Corroded or loose connector terminals at the valve or at the control module, raising resistance and heat in the driver circuit.
A failing control module driver stage that can no longer regulate current properly, often caused by repeated exposure to a shorted valve.
Internal valve mechanical binding that forces the solenoid to draw excessive current as it tries to move the spool.
Contamination or debris in the refrigerant circuit that restricts valve movement and increases solenoid load.
Extreme underhood temperatures or a missing heat shield that pushes the driver circuit beyond its thermal design limit.

How to diagnose and fix it

Verify the stored code and freeze-frame data with a scan tool, then clear the code and test-drive with the A/C commanded on to confirm whether it returns immediately or only after a heat soak.
Inspect the valve connector and the control module connector for corrosion, pushed-back terminals, or melted plastic, and repair any damaged pins before replacing parts.
Measure the resistance of the refrigerant distribution valve solenoid with a multimeter and compare it to the manufacturer's specification to rule out an open or shorted winding.
Check the control circuit for continuity to ground and for short-to-voltage faults with the key on and the module disconnected, repairing any chafed or pinched wire sections.
Command the valve through the scan tool's bidirectional controls and observe current draw and driver temperature parameters to see whether the fault is intermittent or hard-failed.
If the circuit and valve test good, substitute a known-good control module only after confirming that the original driver was not damaged by a shorted valve, to avoid repeating the failure.
After repairs, clear the code, run the A/C through several full hot-to-cold cycles, and verify that the driver current and temperature stay within limits before returning the vehicle.

What the driver current reading really tells you

A valve that is mechanically stuck often draws high current without setting a circuit code for open or short, so technicians who only check resistance miss the real cause.
The driver temperature calculation is a model-based estimate inside the module, not a direct sensor reading, so a code for high temperature can appear even when the valve itself is electrically sound.
A shorted valve winding can damage the control module driver, and replacing only the module without finding the shorted valve will cause the new module to fail in the same way.
Refrigerant distribution valves on dual-loop systems can fail intermittently with temperature, so a cold engine may pass every test while a fully heat-soaked engine sets the code within minutes.
This code can be set by a low refrigerant charge that causes the valve to hunt continuously for a position, so always verify system pressures before condemning the valve or the module.

Can I keep driving with P266F?

You can usually drive the vehicle with this code because it does not affect engine safety, but avoid using the A/C until the fault is repaired to prevent further damage to the control module driver. If the compressor clutch cycles rapidly or you smell hot wiring, stop using the A/C immediately and have the circuit inspected.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.