Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there is a problem with the part of the car that helps control the engine's temperature. It's like when a water valve in your house doesn't open or close properly.
The P26AC code indicates that the engine control module (ECM) has detected an issue with the control circuit of the engine coolant bypass valve B, which could be due to an open circuit.
The engine coolant bypass valve B is responsible for regulating the flow of coolant around the engine to maintain optimal operating temperature. An open circuit or fault in the control circuit can prevent the valve from functioning correctly, leading to potential engine overheating or inefficient temperature regulation.
• Check Engine Light is on
• Engine overheating
• Poor fuel economy
• Erratic engine temperature readings
• Faulty engine coolant bypass valve B
• Open or shorted wiring in the control circuit
• Poor electrical connection at the valve
• Faulty ECM
ECM: Engine Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the P26AC code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the engine coolant bypass valve B for proper operation.
• Check for continuity in the control circuit.
• Repair or replace damaged wiring or connectors.
• Replace the engine coolant bypass valve B if faulty.
• Ensure all electrical connections are secure.
• Replace the ECM if all else fails and the problem persists.
• OBD-II scanner
• Multimeter
• Wrench set
$150 - $400
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regularly inspect coolant system components.
• Ensure coolant levels are maintained.
• Perform routine vehicle maintenance.
Sensor Issue
• Avoid driving the vehicle until repaired to prevent engine damage.
• Consult a professional mechanic for diagnosis and repair.
Check with the vehicle manufacturer for specific warranty coverage related to the cooling system components.
This code has been associated with vehicles that have complex cooling systems designed to improve fuel efficiency and emissions.
High – Ignoring this issue can lead to engine overheating and severe damage.
Operating a vehicle with an unresolved cooling system issue can lead to safety hazards and potential legal liabilities if it results in a breakdown on public roads.
• Engine must be at operating temperature.
• Vehicle should be stationary with the engine running.
The engine coolant bypass valve B is typically located near the engine block or the thermostat housing.
Q: Can I drive with a P26AC code?
A: It's not recommended to drive with this code as it can lead to engine overheating.
Q: How do I reset the P26AC code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue is fixed, it should not return.
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Fitment Required · Vehicle-fitment part
Relevant when coolant-temperature and warm-up faults indicate a thermostat-related issue.
Coolant-temperature and warm-up faults often lead to thermostat testing and replacement.
Thermostats are vehicle-specific and should be matched by engine and housing style.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.