What is P0381 fault code and what does it mean? What is the definition of Glow Plug / Heating Indicator Circuit Malfunction How do you fix the P0381 fault code What are the symptoms and causes for the P0381 fault code
What is the P0381 fault code? What does it signify?
OBD-II-equipped diesel vehicles have one glow plug per piston. Some applications may have less glow plugs in the intake manifold, or cylinder head. The powertrain control unit (PCM), controls the glow-plug heater voltage. There may also be an independent heater control unit in certain applications.
Glow plugs have the job of raising the temperature of the combustion chambers when the engine temperature is below the minimum temperature threshold. This allows the mixture to ignite. To determine when the ignition is switched on, the PCM uses an engine coolant temperature sensor.
A special warning light is installed on all diesel vehicles. This warns you when the glowplugs are on. The light turns on when the ignition is switched on, and then goes off when the engine starts. The glow plug indicator signals to the driver that the plugs are functioning.
The nature of faults in the circuit or glow plug may cause the light to stay on occasionally or not at all, but it is possible for the light to turn on and off depending on the reason. If the light does not turn off, it could cause engine damage. The glow plugs can be damaged by heat, premature ignition, and excessive heat. The engine could run rough or not start in cold conditions if the light does not turn on.
If the PCM detects an issue in the circuit controlling the glow-plug/heater indicator it will set a code P0381 to illuminate the check engine light and notify the driver.
The P0381 fault code can affect vehicles of all makes and models, including but not limited to: Hyundai, Mitsubishi, Ford. Dodge. Chevrolet. Duramax. Opel. Isuzu.
What are the Possible Causes for the P0381 Fault code?
Here are some reasons why P0381 should be set.
- Defective glow-plug
- – A defective glow plug relay
- – If applicable, defective glow plug timer/modul
- – Connectors and wires that are damaged, shorted, disconnected or corroded in the glow plug heater circuit
- Blowing fuse (usually for another reason).
- Defective ignition switch
- – Defective engine coolant temperature sensor(s)
- – Low voltage caused by cables connecting to batteries
- Defective glow bulb warning bulb
What are the symptoms of the P0381 Fault code?
You may experience the following symptoms if your vehicle has the code P0381:
- – Illumination for the check engine light
- – Warning light for glow plugs: No or not
- – Difficulty starting engine, especially in cold conditions
- – Engine makes strange sounds during start-up
- – Exhaust white smoke
How to Fix the P0381 Fault Code
It is very rare for all the glow plugs to fail simultaneously in an engine. If all of the glow plugs fail, it’s most likely an electrical problem. You should first check the components, such as relays, cables, and fuses.
There are several repairs that can resolve the P0381 fault code.
- Repairing a defective glow plug
- Relay for a defective glow plug
- – Replacing a defective glow plug timer/modul
- – Replacing blownfuses
- Repair of damaged wiring, loose or rusty connectors, and open or short circuit problems in the glow plug heater circuit
How Serious Is the P0381 Fault Coding?
Code P0381 will cause the glow plug to stop working. This is a serious condition. Faulty glow plugs can result in the vehicle not starting at all and you being left stranded in cold conditions. It is recommended that you fix the problem as soon as possible.
