Can A Bad AC Compressor Cause Check Engine Light, AC compressor

Can A Bad AC Compressor Cause Check Engine Light

I was cruising down the highway on a scorching summer day. Suddenly, out of nowhere, the check engine light starts glaring at me from the dashboard. There were some problems associated with my AC system. So, the quick question that came to mind was, “Can a bad AC compressor cause check engine light?”

A bad AC compressor typically does not directly trigger the check engine light. The check engine light is primarily associated with issues related to the engine and its emissions system. There are circumstances, though, in which a broken AC compressor can indirectly turn on the check engine light.

Through thorough research, I was able to find out how the AC compressor causes the check engine light to come on. In this article, I will explain that and mention some important things I found in the research.

What is an AC compressor?

Ac compressor

An AC compressor, or air conditioning compressor, is a vital component of an air conditioning system. It plays a crucial role in the refrigeration cycle by compressing the refrigerant gas and circulating it through the system. The compressor is typically driven by the engine of a vehicle using a drive belt, although electric motors can also be used in certain applications.

What Is the Duty of the AC Compressor?

The primary function of the AC compressor is to increase the pressure and temperature of the refrigerant gas. It draws in low-pressure, low-temperature refrigerant vapor from the evaporator and compresses it into high-pressure, high-temperature gas. This compression raises the energy level of the refrigerant, allowing it to release heat more efficiently.

How does AC compressor work?

The compressed refrigerant gas then flows to the condenser, where it undergoes a phase change from gas to liquid. As the high-temperature gas enters the condenser, it releases heat into the surrounding air or cooling medium, causing the refrigerant to condense into a high-pressure liquid.

What Are the Symptoms of Faulty AC Compressor?

Here are the signs and possible causes of a problematic AC compressor. 

SymptomPossible Cause
Rumbling noiseBad bearings in the AC compressor
Blows warm airDebris on cooling fans
A burned coil in the AC compressor
AC compressor spins but doesn’t compress refrigerantIneffective compression inside the AC compressor Clutch deterioration due to excessive heat
Failed solenoid valve in solenoid control compressorsMalfunctioning solenoid valve in solenoid control compressors
Compressor not spinning in variable displacement compressorsDisruption in variable displacement compressor operation
AC compressor turns, but the clutch slipsClutch slipping
Black death situationSevere damage or seizure of the AC compressor

Let’s discuss them.

Rumbling Noise

This can be attributed to bad bearings. This refers to a noise that occurs when the AC system is activated. It indicates that the bearings within the AC compressor may be worn or damaged.

Blows Warm Air

When the AC powers on but only blows warm air, it suggests that debris is accumulated cooling fans or coil within the AC compressor may be burned. This can prevent the clutch from engaging properly, resulting in the compressor not compressing refrigerant and producing cold air.

Doesn’t Compress Refrigerant

This symptom describes a situation where the AC compressor is turning but fails to compress the refrigerant properly. As a result, the AC system does not produce cold air, even though the compressor appears to be functioning.

Fried or slipping Clutch

If the compressor doesn’t work it problem should be on the clutch. A fried clutch occurs when the friction between the flywheel and the clutch generates excessive heat, causing the rubber holding them together to deteriorate. As a result, the clutch fails to engage properly, preventing the compressor from compressing refrigerant effectively.

The slipping clutch fails to provide sufficient power to the compressor, resulting in reduced cooling performance.

Failed Solenoid Valve in Solenoid Control Compressors

Ac compressor solenoid valve

Solenoid control compressors rely on an electronic solenoid valve to regulate the flow of refrigerant. If the solenoid valve fails, the compressor may continue to rotate without actually pumping refrigerant, resulting in a lack of cooling.

Compressor Not Spinning in Variable Displacement Compressors

Variable displacement compressors have a clutch and a solenoid control valve. If the compressor fails to spin despite being properly connected, it indicates a problem. This issue can disrupt the AC system from functioning correctly.

Black Death Situation

Black death refers to a condition where the AC compressor becomes severely damaged or seized up, causing it to stop moving entirely. When this happens, the compressor fails to function, leading to a lack of cooling.

How Does a Bad AC Compressor Cause Check Engine Light?

In modern vehicles, the AC system is often connected to the engine management system. If there is a significant problem with the AC compressor, such as a seized or locked-up compressor clutch, it can put excessive strain on the engine. This increased load on the engine may lead to irregular engine operation, misfires, or other issues that can trigger the check engine light.

Additionally, some vehicles are equipped with sensors or switches that monitor the AC system’s performance. If these sensors detect abnormalities, such as low refrigerant levels or excessive pressure, they may communicate with the engine management system and trigger the check engine light.

Note: It’s important to note that the check engine light can be triggered by a wide range of factors, and a faulty AC compressor is just one of many potential causes.


Can car AC compressor be repaired?

While repairs may be possible in certain instances, it is generally recommended to opt for a replacement. Replacing the faulty compressor with a new one tends to be a more time-effective solution that offers better long-term results.

Repairing an AC compressor can be a complex and time-consuming process. It involves diagnosing the specific issue, disassembling the compressor, replacing the faulty parts, and reassembling everything. This approach may provide a temporary fix, but it doesn’t guarantee a lasting solution.

What is the most common problem with the car AC compressor?

The most frequent issue encountered with car AC compressors is leaks in the air conditioning system. When the pressure is low in the AC system, it often indicates the presence of a leak. A convenient method to identify leaks is by employing a UV A/C leak detection kit. This tool allows for easy detection of leaks within the AC system.

What causes AC compressor failure in car?

AC compressor failure in cars can be caused by various factors. One common cause is clogs in crucial components such as valves, filters, or condensers. When these parts become clogged, it restricts the airflow and leads to a loss of pressure within the AC system.

As a result, the AC compressor may overheat due to insufficient airflow over the vents inside the vehicle’s cabin space. This overheating can eventually lead to compressor failure.

What does a solid check engine light mean?

A steady check engine light typically points to a non-emergency problem. Common examples include a loose or improperly tightened gas cap, which can cause a minor fuel system leak. In such cases, tightening the gas cap securely should resolve the issue. However, it’s still important to address the problem to prevent any potential long-term effects on your vehicle’s performance or fuel efficiency.


While a bad AC compressor itself may not directly cause the check engine light to illuminate, it can indirectly contribute to issues that trigger the light. Ultimately, addressing a bad AC compressor is crucial not only for the proper functioning of the vehicle’s air conditioning system but also for the overall performance and efficiency of the engine.

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