Navigating through the complexities of car maintenance can be challenging, especially when confronted with specific error codes like the P1326 Glow Relay Stuck on Kia Optima.

What is the P1326 Code?

The P1326 code is a diagnostic trouble code (DTC) related to diesel engines’ glow plug relay systems. It indicates that the glow plug relay, which aids in heating the engine during cold starts, is stuck in the “on” position. This malfunction can lead to various operational issues, including potential damage to the glow plugs and excessive battery drain.

What is the P1326 Code

Read more about Battery Light On But Car Runs Fine: How to Diagnose and Respond to Your Vehicle’s Silent Alert

Causes of P1326 Code

The P1326 code, particularly when referenced with vehicles like the Kia Optima, can stem from several issues, all related to the glow plug system in diesel engines or knock sensor problems in gasoline engines. Specifically, for the context of the “P1326 Glow Relay Stuck On” scenario, the causes are generally focused on the diesel engine’s glow plug system. Here are the primary causes:

Faulty Glow Plug Relay

The direct cause of the P1326 code is often a malfunctioning glow plug relay. This relay provides power to the engine’s glow plugs during startup, especially in cold conditions. If the relay fails to shut off or is stuck in the “on” position, it can lead to continuous power being supplied to the glow plugs, potentially causing overheating and damage.

Also read How To Fix And Reset Check Emission System Acura TSX? 8 Common Causes of the Emission System Alert

Damaged Wiring or Connectors

The electrical circuit to the glow plug relay includes various wires and connectors that can become damaged over time. Corrosion, fraying, or breaks in the wiring can impair the proper operation of the glow plug relay, leading to it being stuck in the “on” position and triggering the P1326 code.

Faulty Glow Plugs

While the P1326 code primarily indicates a problem with the glow plug relay, issues with the glow plugs can also contribute. If one or more glow plugs are faulty and fail to heat up properly, the relay might remain active in an attempt to compensate, potentially leading to the code being set.

Control Module Issues

The engine control module (ECM) controls the operation of the glow plug relay based on input from various sensors. If there’s a malfunction within the ECM, it can incorrectly operate the relay, causing it to remain on indefinitely.

Software Glitches

Modern vehicles rely heavily on software to manage engine and emission control systems. A glitch or bug in the vehicle’s software can lead to erroneous operation of the glow plug relay. In some cases, a software update from the manufacturer may be necessary to resolve this issue.

Excessive Engine Wear or Low Oil Pressure

Specifically related to the knock sensor aspect of the P1326 code in gasoline engines, excessive engine wear or low oil pressure can lead to abnormal engine operation that the knock sensor interprets as knocking, potentially setting off related codes.

Symptoms of the P1326 Code

The presence of the P1326 code, indicating a glow relay stuck on or related issues in vehicles such as the Kia Optima, can manifest through several symptoms. Recognizing these symptoms early can aid in timely diagnosis and repair, potentially avoiding more significant engine problems. Here are the common symptoms associated with the P1326 code:

Difficulty Starting the Engine

It is especially noticeable in colder weather; the engine might have trouble starting if the glow relay is stuck. The glow plugs may be worn out or damaged due to the constant power supply, affecting their efficiency in heating the combustion chamber for a cold start.

Check Engine Light

One of the most immediate signs of the P1326 code is the illumination of the check engine light on the dashboard. This light is triggered by the engine control unit (ECU) when it detects the glow relay issue, among other potential engine problems.

Increased Fuel Consumption

A malfunctioning glow plug system can lead to inefficient combustion, especially during the engine warm-up phase, resulting in higher fuel consumption.

Engine Misfires

If the problem causes uneven heating of the combustion chamber due to faulty glow plugs, it may lead to engine misfires. This is more prevalent during startup and the initial driving phase until the engine reaches its optimal operating temperature.

Reduced Engine Performance

Overall engine performance may decline, with reduced power and acceleration symptoms. This can be attributed to the compromised efficiency of the engine’s combustion process due to issues with the glow plug system.

Battery Drain

If the glow relay is stuck in the “on” position, it can lead to excessive battery drain, as the glow plugs continue to draw power even when the engine is off or has reached operating temperature.

Overheating Glow Plugs

Continuous power supply can lead to glowing plugs overheating, which might be noticeable by a burning smell or, in severe cases, visible damage to the plugs upon inspection.

Diagnosing P1326 Code

Diagnosing the P1326 code, especially in vehicles like the Kia Optima, requires a systematic approach to identify the root cause of the issue accurately. Here’s how professionals typically diagnose this problem:

Read the Codes

The first step involves using an OBD-II scanner to read the error codes stored in the vehicle’s computer. This confirms the presence of the P1326 code and may also reveal other related codes that could shed light on the underlying issue.

Visual Inspection

A thorough inspection of the glow plug system, including the glow plug relay, wiring, and connectors, is crucial. This can help identify any signs of wear, damage, or corrosion causing the problem.

Check the Glow Plug Relay

The relay should be tested for proper operation. This involves checking if it’s stuck in the “on” position, as the code indicates. A multimeter can measure voltage and ensure the relay is opening and closing correctly.

Inspect Glow Plugs

Each glow plug should be individually tested for continuity and resistance. A glow plug that fails these tests is likely faulty and could contribute to the issue.

Wiring and Connectors

All associated wiring and connectors should be checked for damage, corrosion, or loose connections that could interfere with the proper operation of the glow plug system.

Engine Control Module (ECM) Check

Since the ECM controls the operation of the glow plug relay, it’s important to ensure that the ECM functions correctly. This might involve checking for software updates or diagnosing the ECM for faults.

P1326 Code Repair and Solutions

Once the diagnosis is complete, the next step is to address the P1326 code with the appropriate repairs or solutions. Here are the common fixes:

Replace the Glow Plug Relay

If the relay is faulty or stuck in the “on” position, replacing it is usually the most straightforward fix.

Repair or Replace Wiring

Any damaged or corroded wiring and connectors should be returned to ensure a solid electrical connection to the glow plug relay and plugs.

Replace Faulty Glow Plugs

If any glow plugs are found to be defective during the diagnostic process, replacing them will help ensure efficient engine startup and operation, especially in cold conditions.

ECM Software Update

If the issue is related to a software glitch in the ECM, a software update from the manufacturer may resolve the problem.

Check for Additional Codes

If other codes were found during the initial scan, addressing those might also be necessary to resolve the P1326 issue fully.

Professional Assistance

Due to the complexity of modern vehicle electrical systems, seeking assistance from a professional mechanic or dealership service center is often advisable, especially for in-depth diagnostics and ECM-related repairs.

FAQs on P1326 Glow Relay Stuck on Kia Optima

How do you fix the P1326 error code in Kia vehicles?

Replacing the glow plug relay and ensuring all wiring is intact and functioning properly are the first steps toward resolving the P1326 error code in Kia vehicles.

What does the P1326 error code indicate in Hyundai Tucson?

Like the Kia Optima, in the Hyundai Tucson, the P1326 error code signifies a malfunction with the glow plug relay stuck in the “on” position.

What is the location of the glow relay in Kia Optima?

The glow relay in Kia Optima is typically located in the engine compartment, near the battery or fuse box.

Is there a recall for the P1326 issue in Kia Soul?

For information on specific recalls, it’s best to check with the official Kia website or contact a Kia dealer, as recall actions can vary based on model year and identified issues.

How does P1326 affect a 2017 Kia Sportage?

In a 2017 Kia Sportage, the P1326 code can lead to difficulty starting the engine during cold conditions and might cause unnecessary wear on the glow plugs and battery.

Does Kia offer a warranty for the P1326 issue?

Warranty coverage for the P1326 issue will depend on the specific terms of your Kia warranty. It’s advisable to contact a Kia service center to determine if your situation is covered.


The P1326 Glow Relay Stuck on Kia Optima error code should not be ignored. Understanding and promptly addressing its implications can save you from potential headaches and ensure your vehicle’s longevity and performance.


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