Behind The P1326 Glow Relay Stuck on Kia Optima: A Breakdown

The P1326 glow relay stuck on Kia Optima doesn’t often occur, especially for well-maintained cars. But once it does, this code can be the death of your driving experience.

Buckle up, tighten your seatbelt, and dive in to learn our take on its meaning, possible causes, and corresponding solutions.

What Does The Fault Code P1326 Kia Optima Mean? Is It Serious?

p1326 glow relay stuck on kia optima
Code P1326 Kia Optima

P1326 – set by the ECM (Engine Control Modules) – is activated when the Knock Sensors Detection System spots abnormal vibrations from the car.

In short, this exact code will manifest itself whenever there is too much engine vibration than required on Hyundai or Kia vehicles.

On another note, the P1326 error code for diesel-engine Kia also signifies certain issues with their glow plug relays – a device designed to heat engine cylinders in cold weather.

Their operation failure might cause difficulties in engine starting and worsened performance.

Is it serious? “Yes” is an understatement. Treat the code as fast as you can – unless you wish the faulty glow plug/engine ignition system to destroy your car completely.

And even if it doesn’t, the increased emissions and bad fuel efficiency are torturous enough; only a fool would invite such disasters to happen to them.

What Are The Symptoms of P1326 Glow Relay Stuck on Kia Optima?

During earlier stages, you might only notice trivial, fleeting symptoms – such as check engine lights flickering, limp mode, or limited engine speed that does not allow the acceleration to be as smooth as usual.

Without proper treatment, those signals will only get worse over time.

Here is the full list of P1326 symptoms to look out for: 

What Are The Causes and Solutions for P1326 Glow Relay Stuck on Kia Optima?

kia optima p1326 code
Causes and Solutions for P1326 Glow Relay Stuck

Quick answers: mechanical problems, wiring issues, and broken knock sensors should be the first place to look into.

Replacing or cleaning them is the quickest and most efficient solution, though the pricing might give tight-budget customers quite a headache.

So if you have the skills required, look up online instructions for DFY replacements.

Bad Knock Sensors

Each Kia Optima features knock sensor systems to alert drivers of serious engine crank problems before the rods are eventually thrown.

But once those sensors break down, they will trigger false alarms due to wrong data readings, which inevitably throw a false code.

Since they all boil down to mere mechanical issues, replacing the sensors/rod bearings should be the best way to clear P1326. There’s only one problem: the cost.

Hence, if you have sufficient technical experience, we strongly suggest scouring through Youtube guides to reinstall them yourselves.

After all, the sensors are often located on the block’s side – super easy to access.

An important note during replacements: knock sensors often use ceramic to assess severe engine damage: over-torquing the device over specs may break that delicate ceramic layer, making the sensors oversensitive to even the slightest vibration.

Hence, always ensure the torque spec is light, not beyond a snug.

Also, in emergency cases, you may attempt a knock sensor bypass (like with Chevy). However, note that these are only temporary resorts and can never reach the core of P1326 problems.

Wiring Harness Issues

Like any car compartment, the wiring harnesses traveling across the sensor may break down over time (understandable, as it has gone a pretty long distance on its own).

Thus, remind yourself to double-check them for burnt, frayed, or cracked wiring, and pay special attention to where the plugs are hooked into the sensors.

Tabs in great shape mean things are still fine. Replace or clean them immediately if they seem oxidized or turn a pale green. Another great tactic is to splice it into new connectors.

Mechanical Problems

None of the two issues above apply to your case? Then chances are the rod bearings (or other relevant parts) have been broken.

Even some highest-end models are subjected to them due to excessive usage and bad weather!

At that point, the safest bet is to bring the car to dealerships and have trusted professionals inspect it.

Kia does offer powertrain warranties for certain defects, so research carefully to save repair costs.

How to Diagnose P1326 Kia Code

2015 kia optima p1326
Way Confirm P1326 Kia Code

Self-diagnosis at home is optional, but it can help mechanics speed up the troubleshooting process later.

The process is also straightforward and barely takes more than a few minutes; there’s no reason not to give it a try! 

Step 1. Use scan tools (like an OBD-II scanner) to erase the P1326 code from the car’s computer.

Step 2. Kick-start the entire engine till its check engine lights flicker back on.

Run your code scanner again; if other faulty codes are also present, note them down to investigate/tell the ASE certified technician later.

Step 3. Check the ECM’s software update. Is it not the most recent version? Update it yourself, or have it changed by a Kia dealership.

Step 4. Inspect all knock sensors’ wiring and connections. Should there be anything immediately fixable, do it right away. If not, leave it to the mechanics.

Step 5. Measure and inspect the sensors’ resistance, usually below the intake and above the gasoline engine blocks. Check Kia’s repair manual to identify the correct value.

And when none of these steps can deduce whatever causes behind  the P1326 glow relay stuck on Kia Sportage, it’s time to reach out for further professional guidance.

Chances are something really bad has led to the car’s severe engine failure, and only experts can detect/diagnose it.

FAQs: Quick Questions

Has There Been Any Recall for Kia P1326 Glow Relay Stuck On? 

No, but there have been product improvement campaigns to fix the P1326 Kia Optima glow relay stuck on in these models:

  • Sorento/ Optima 2014
  • Sorento / Sportage 2013
  • Optima 2013
  • Optima/ Sportage 2011
  • Optima/ Sportage; Sorento 2012

Does Kia Warranty Cover The Kia Optima P1326 Code?

Yes. The manual does mention an extended warranty for short-block assemblies, including rod bearing wear and connecting rods (the features often associated with the Kia Optima P1326 codes).

Nevertheless, there might be other conditions you must fulfill to qualify for the warranty. Confirm this matter with your manufacturer first.


Our take on the P1326 glow relay stuck on Kia Optima has presented a few potential causes behind the issue – accompanied by quick fixes and solutions.The rest should be a no-brainer, even for beginners.

Still, if you find yourself stuck, feel free to reach us or the Kia support team for more P1326 Kia Optima fix.

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