P1299 Code – Meaning, Symptoms, Causes And How To Fix It?

Written By: Terrence Hines
Category: Error Code

P1299 code is an error code created when a problem arises with the vehicle’s internal combustion engine or the engine’s cooling system.

P1299 code-related problems will need either new parts or a lot of maintenance, like cleaning the cooling system components. Thus, with the right solutions, P1299 can be fixed.

What Does The P1299 Code Mean?

P1299 code is a diagnostic trouble code (DTC) issued by the vehicle’s powertrain control module, indicating an issue with the engine’s cooling system.

The P1299 code means there is a problem with the part of the car that helps control how much pressure is in the cooling system. This could be the thermostat, radiator fan, or water pump.

What Does The P1299 Code Mean?

P1299 can cause serious damage if not fixed. For example, if it is not fixed and the machine continues to be used, the cylinder head or engine block could become warped or cracked.

Fortunately, the P1299 code can usually be resolved relatively quickly and inexpensively by replacing the faulty part and flushing the coolant system.

Before attempting any repairs, it’s important to retrieve the necessary codes from your vehicle’s onboard computer to accurately diagnose P1299 before doing any work.

Symptoms Of The P1299 Code

If your car displays a P1299 code, your vehicle could be experiencing multiple issues. This code tells us that something is wrong with the engine.

Many things could be wrong, like poor fuel economy or acceleration, a change in idle speed, or the check engine light coming on.

Other signs that your car has an EGR system problem are: it has trouble accelerating, you hear strange noises from the engine area, and it is hard to start or keep running.

If you are experiencing any of these warning signs it is important to inspect your engine as soon as possible to ensure your vehicle’s safety.

1. Illumination Of The Check Engine Light:

P1299 is a diagnostic trouble code (DTC) that often indicates an issue in the engine cylinder.

If this P1299 code appears, one of the symptoms is the illumination of the check engine light on your vehicle’s dashboard.

This warning alert should not be ignored as it signals a need for action; if left unresolved, your car may suffer further damage or become inoperable.

It is important to read the code diagnostics and repair them immediately. To diagnose P1299 codes, you need to find a professional to help you find the cause and recommend solutions.

2. Misfiring Or Rough Idling/Running:

Regarding P1299 codes, a common symptom is misfiring or rough idling/running.

If your vehicle is experiencing these issues, you’ll be able to notice unusually loud and rough engine noise when your car is running.

Additionally, idling may become more unsteady with the dashboard lights flickering off and on.

The P1299 code can occur when a spark plug is unresponsive or damaged in whatever way, so don’t hesitate to bring your vehicle in for an examination if you spot any of these signs.

3. Poor Acceleration:

Drivers who experience poor acceleration could be dealing with a P1299 code.

This code indicates that a system controls air flow into the vehicle’s engine, and there is an issue with how it functions.

Symptoms such as low acceleration, stalling, hesitating or surging when trying to speed up, and decreased power are all common signs that there is a problem with the vehicle.

Diagnosing P1299 accurately and promptly is essential to correctly repair the problem and ensure safe vehicle operation while driving.

4. Increased Exhaust Smoke/Odor:

An indication of the P1299 code is often the smell and sight of increased exhaust smoke.

Increased Exhaust Smoke/Odor

This indicates a problem with the cylinder head temperature sensor circuit, which can lead to the vehicle running inefficiently and burning fuel more easily, reducing its overall performance.

When these symptoms are present, it is best to have the car serviced immediately to prevent further damage.

Accurately diagnosing the source of the P1299 code will help ensure that repairs result in full recovery from this condition.

5. Reduced Fuel Economy:

If your vehicle is experiencing reduced fuel economy, it could be due to a P1299 code. Known as a “System Too Lean”, this diagnostic code can be thrown when the engine runs too lean.

This means that the air-to-fuel ratio is off, causing the vehicle to use more fuel than it normally takes.

While P1299 codes don’t necessarily point to an exact issue, they do serve as good indicators of potential problems with your car’s air-to-fuel ratio.

If you’re experiencing reduced fuel economy due to P1299 codes, it would be smart to make an appointment with a certified mechanic for diagnosis and repair.

Common Problems That Can Cause The P1299 Code

P1299 is a code that could indicate several potential issues with your vehicle.

Problems that can cause the P1299 code include issues in the exhaust system, such as a failed oxygen sensor, a misfiring spark plug, and excessive amounts of oil entering the combustion chamber.

Other underlying problems in the fuel injector or powertrain control module can also trigger P1299.

It is important to visit a trusted mechanic if P1299 appears on your vehicle’s system, as this code could indicate serious, unresolved problems in your car’s performance.

1. Malfunctioning Intake Manifold Gasket:

The P1299 code is generated when your vehicle’s engine has a malfunctioning intake manifold gasket.

The P1299 code indicates that there may be a problem with either the gasket or the system in which it serves.

A leak in the intake manifold gasket can cause air to enter the combustion chamber, reducing engine power and causing your vehicle to misfire.

 The P1299 Code

Furthermore, this will also increase pressure within the intake manifold, triggering other related fault codes as well.

If your car is not working right because of the intake manifold gasket, you must take it to a professional to fix it. If you don’t, it could break more and cost more money to fix.

2. Bad Spark Plugs/Wires/Coil Packs:

P1299 code is an error code thrown by the car’s computer system when it detects a problem with the ignition system.

The P1299 code can appear when the spark plugs, wires, or coil packs are not working well. These parts need to be replaced every so often to keep the vehicle running efficiently.

Faulty spark plugs, worn-out wires, and failing coil packs may all lead to P1299 codes, which can impair driving at best and cause irreparable harm.

If the P1299 code has shown up on your car’s diagnostics screen, ensure you get somebody reliable to check your spark plug and wire systems.

3. Damaged/Clogged Fuel Injectors:

P1299 code is a common error code that can occur during engine malfunction. Sometimes, P1299 could be caused by a damaged or clogged fuel injector.

Fuel injectors dispense fuel at the exact right moment and in the correct amounts to ensure efficient combustion.

When fuel injectors become blocked, they prevent the proper flow of gasoline into the engine and consequently impact its performance.

A blockage or harm in your fuel injector will bring about an error code P1299 since something is amiss with your combustion system.

P1299 needs to be diagnosed promptly to restore your vehicle to normal functions and prevent other serious damage from occurring.

4. Faulty Oxygen Sensor(S):

P1299 code is a common trouble code associated with a problematic Oxygen Sensor.

This trouble code means that too much oxygen has been detected in the exhaust system, and thus the Engine Control Unit (ECU) has adjusted the air-fuel ratio accordingly.

The P1299 code typically appears when there is an issue with one or more of your vehicle’s Oxygen Sensors due to their wiring or simply having worn out over time.

If this problem is not fixed immediately, it could cause more damage to other parts of the car’s engine.

That is why it is important to identify P1299 codes early and take action to replace the broken Oxygen Sensors as soon as possible.

5. Vacuum Leaks:

Vacuum leaks are one of the most common reasons behind the P1299 code.

This code indicates that the engine is running overly rich, meaning it receives excessive fuel relative to air.

This can be caused by certain parts in the system not functioning correctly or being damaged.

Vacuum leaks can be an issue when rubber hoses and connectors become old and brittle, eventually leading them to break apart or become loose.

If a vacuum leak is at fault, the P1299 code should go away after replacing the vacuum hoses and/or replacing any faulty seal or gasket to restore proper operations.

How To Fix The P1299 Code?

If your car displays the P1299 code, you are likely experiencing trouble with the engine’s cylinder head temperature, as this code relates to an overheated engine head.

Fortunately, there are several steps you can take to fix this issue.

The first step is to check for any faulty sensors by running a diagnostic and listening for any unusual noises coming from the engine.

How To Fix The P1299 Code?

If a sensor is malfunctioning or disconnected, replacing or reconnecting, it should restore the P1299 code to normal levels.

If the P1299 code persists, coolant flow may be at fault and can generally be corrected by refilling fluid levels and checking hoses and thermostat connections.

Finally, in some cases, P1299 can occur due to worn-out components such as spark plugs, coils, or injectors, which will require replacement to resolve the issue.


 P1299 code is an indication that there may be an issue with the engine’s combustion chamber or temperature control.

If the P1299 code appears, it’s important to take your car to a qualified technician as soon as possible to determine the exact cause of the problem.

Once located and fixed, your vehicle should experience improved performance and fuel economy. But, more importantly, it will reduce the engine’s short-term and long-term damage.

Terrence Hines

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