P0671 - GLOW PLUG, CYLINDER 1 - CIRCUIT MALFUNCTION

In gasoline engines, the spark plugs are used to burn the fuel. On the other hand, diesel engines, although they do not use spark plugs because the fuel is burned by compression, they do have glow plugs. These components are very important for diesel engines when working in cold weather.

The main function of the heaters is to increase the temperature of the engine, especially during cold weather or if the engine has been idle for a certain time. It should be noted that the diesel engine needs a high level of heat because diesel just explodes under high compression at high temperatures. These heaters also reduce engine emissions by up to 49% because with the engine at a warmer temperature, the fuel burns easily.

The Fault code P0671 OBDII indicates that there is a problem in the glow plug circuit, resulting in the number 1 cylinder plug not heating up.

• Check Engine light illuminated.
• Difficulty starting the engine, especially during cold weather.
• Remarkable power loss until the engine reaches a higher temperature.
• Hesitation when accelerating.

The reasons why the DTC code P0671 OBD2 is set are the following

• The spark plug circuit may be shorted.
• Maybe the connector or cable is defective.
• Cylinder 1 spark plug in bad condition.
• The control module of spark plugs with defects.

To solve the problems of the diagnostic code P0671 OBDII, take into account the following suggestions to fix it:

• Unplug the glow plug connector and connect a DVOM (Digital Volt-Ohm Meter). You should see that the reading is between 0.5 and 2.0 ohms. Check the specifications for the required voltage. If it is not within the range indicated by the manufacturer, you should change the glow plug.
• Check the resistance on the glow plug wire to the glow plug relay. Check the cable and take into account that the reading should be between 0.5 to 2.0 ohms, being 2 ohms the highest resistance. If it's higher, you should change the spark plug wire.