P0126 OBD Error Code: Problem & Solutions

<<See All OBD Codes

Inadequate engine heat-up time, a coolant temperature sensor defect, a low engine coolant condition, or a thermostat error could cause this.

ECT sensor readings that happen after the OBD-II system has been sent into closed loop operation, and are lower than the manufacturer’s defined value, will cause a trouble code to be stored and a malfunction indicator lamp to be illuminated.

What causes this problem with the Throttle Position Sensor/Switch A Circuit?

• Low Level Engine Coolant
• Thermostat Stuck Open or Leaking
• Defective Engine Coolant Temperature (ECT) sensor
• Engine Coolant Temperature (ECT) sensor harness is shorted or open
• Engine Coolant Temperature (ECT) sensor electrical circuit in bad connection

1. Boost Pressure Sensor - If the boost pressure sensor starts breaking, you will see the boost is losing power and the engine is decreasing in efficiency. If your boost pressure sensor is damaged for sure, it must be replaced to prevent your turbocharged car from losing its effectiveness.
2. Turbocharger ­- The turbocharger may falter due to low oil levels, which means overheating and friction will eventually disintegrate the bearings from inside. This entails that you need to replace the turbocharger or use internal lubricants to ensure the parts are moving fast and efficiently.
3. Supercharger - A supercharger can begin to fail for a whole range of reasons, such as a poor level of supercharger oil, broken pulley, and overheating or defective seals/gaskets. If your car's supercharger is not performing correctly, you need to have it replaced immediately.
4. Knock Sensor - When examining a knock sensor, be sure there are no corroded terminal or no damaged wires and connections. A defective knock sensor decreases your car’s performance; puts an effect on its fuel economy and produces pricey damage to your engine, so it’s important to get the particular knock sensor for your kind of car demands.
5. Spark Plug - A defective spark plug may happen when acceleration is slow, power is at loss, fuel economy is low, the engine misfires, and the car has trouble starting. As a result, it is highly advised to replace your spark plug for every 30 months or 30,000 miles your car is traveling.
6. Intake Manifold - A leak in the intake manifold can deem obstructive effects on your car's engine, pushing the manifold to suck in extra air from outside through the leak source, causing even more air to enter the intake ports and disrupting with the air-fuel correlation in the cylinders. You should pursue having defective manifold replaced as soon as possible to restrain any chance of more harmful risks on your car's engine.
7. Boost Pressure Gauge - If the boost pressure sensor is faltering, you will see a decline of boost power and reduction in engine efficiency. If your boost pressure sensor is damaged, its highly recommended you replace it to hinder chances that your turbocharged car will lose its efficiency.
8. Powertrain Control Module - A defective PCM could make your car fail to start or begin to stall when running. Inclusively, low emissions can happen when all fails to control the emissions system, so if your PCM is not functioning correctly, you should replace it right away.
9. Engine Control Module - Your car may have trouble starting even after ensuring that its battery and starter are working accurately. If your vehicle’s errors narrow down to a defective engine control module, it’s essential that you have it replaced instantly to stop more severe risks in harming your car.
10. Wastegate - If extra exhaust gas is sent through the turbine, the unit can over-speed, which puts mechanical stress right on it and causes all sorts of problems, for example shafts breaking down, compressor wheels faltering, or a torrent rushing to the engine's internals and power delivery. It’s appropriate to adjust the turbo itself and replace an upscale version with one customized for the job, if practicable.

The TPS engages in an important part of engine drivability, therefore a stored code P0126 should be called forward at a level of swift action. Symptoms of a P0126 code may include:

Common Symptoms

• The Check Engine Light displayed on the instrument panel/dash
• Poor fuel economy
• Overheated car
• Deficient heater performance
• Engine damage

The OBD Code P0126 problems can be fixed with some of these common solutions for your particular car engine:

• It makes no difference what car you have; you should check the appropriate Technical Service Bulletins (TSB) as they relate to your car. For such makes as Mazda, there are a few notable TSBs and the repair method is to reprogram the PCM, as a “glitch” will trigger this code in the PCM's programming. That doesn’t mean that if you own a Mazda, this is not possible to repair. There is still a possibility that there is a physical issue with the wiring, thermostat and other components. To restate, it is best to check the TSBs first in advance to replacing components to observe if they are applicable to your vehicle.
• Detect to make sure cooling fan operation is accurate. The fan should be on when turned on, and should be off when turned off. If the cooling fan is constantly on, it could cause the engine to heat up slowly or not heat up to the correct functioning temperature.
• Detect the engine coolant for the temperature level. It the level is low, top up, clear the code and drive the car to observe if it comes back. Allude to the “freeze frame” data and see the live data by using a code scanner to view the value of the engine temperature sensor. Collate with the manufactures proposals.
• Use a laser thermometer to confirm the temperature of the coolant at close and safe range, and measure the temperature of the engine to collate with the value of the sensor reading.
• Examine for a defected thermostat, coolant temperature sensor (CTS) and wiring. Repair as needed.

It’s beneficial to always check for technical service bulletins (TSB) in advance for your specific car. You may have a known issue with your engine that has a known fix easily sought by the manufacturer that can save you time and money during this diagnosis. It is common to use a diagnostic scanner, a digital volt/ohmmeter (DVOM) and a precise car information source (ALL DATA DIY) to diagnose a code P0126.

• To start with, check to ensure that the engine is contained with enough suitable coolant so that the thermostat is performing accurately
• Start your diagnosis by watchfully checking for all wiring and connectors
• View for wiring that is shorted or burned and exchange circuitry and connectors as needed
• Suppose if the system wiring, connectors, and components look to be working in normal order, connect the scanner to the diagnostic connector and record all retained trouble codes and freeze frame data
• This data can be immensely helpful in diagnosing irregular conditions that could have provided to this code being retained
• After clearing the codes, run the car to see if the code comes back
• If the code fails to return instantly, you might have an irregular condition
• Irregular conditions can uphold as being such a challenge to diagnose and in intense cases may need be enabled to worsen before precise diagnosis is able be made. Detect the fan clutch (if equipped)
• This code is often set because the driver does not enable adequate engine heat up time (especially in cold weather)
• It is a good idea to reset the code and see if it comes back when this code is on display.

Common Mistakes When Diagnosing The P0126 Code

• Faulty Engine Thermostat
• Faulty Engine Coolant Temperature Sensor
• Faulty Intake Air Temperature Sensor
• Faulty Cooling System
• Poor Engine Coolant
• Filthy Engine Coolant, leading inaccurate Coolant Temperature Sensor scanning
• Faulty Engine Cooling fan(s) that are always running