P0680: Glow Plug Control Circuit Cylinder No. 10 DTC

Introduction

The DTC P0680 error code indicates a problem in the glow plug control circuit for cylinder 10. These devices are essential in diesel engines, as they ensure easy starting even at low temperatures. Understanding the causes and symptoms associated with this error is crucial to a correct diagnosis and resolution of the problem.

Symptoms

Symptoms associated with the DTC code P0680 can vary, but the most common include:

  • Difficulty starting the engine, especially when cold.
  • Engine idling erratically.
  • The engine malfunction indicator light (MIL) comes on.
  • Excessive or irregular exhaust fumes during operation.
  • Possible overall vehicle performance issues.

Cause

The causes of the DTC code P0680 can be many and include:

  • Defective glow plugs :
    One or more glow plugs may be burned out or damaged.

  • Wiring problems :
    The circuit wires may be damaged, disconnected, or shorted.

  • Engine control unit (ECU) malfunction :
    The ECU may not be sending the correct signal to the glow plugs.

  • Power problems :
    Inadequate power to the glow plug circuit can cause a malfunction.

  • Faulty sensors :
    Sensors such as the engine temperature sensor can affect the operation of the glow plugs.

Diagnosis

Diagnosing DTC P0680 requires a systematic approach. Here are the main steps:

  1. Vehicle Scan :
    Use a diagnostic tool to confirm the DTC code and identify any related codes such as P0670 (glow plug control circuit) or P0671 (glow plug cylinder 1).

  2. Visual inspection :
    Check the glow plug wiring and connections for signs of wear, corrosion, or damage.

  3. Continuity test :
    Use a multimeter to check the continuity of the glow plug circuit.

  4. Checking the glow plugs :
    Perform resistance tests on each glow plug to ensure they are working properly.

  5. Checking the control unit :
    Check if the engine control unit (ECU) is sending the correct signal, using an oscilloscope if necessary.

Resolution and repair

Once you have identified the cause of the DTC P0680 code, you can proceed with troubleshooting the problem. Possible repairs include:

  • Replacing the glow plugs :
    If one or more spark plugs are defective, it is essential to replace them.

  • Wiring Repair or Replacement :
    If the wiring is damaged, proceed with the necessary repairs or replacements.

  • Replacing the engine control unit (ECU) :
    If the control unit is not working properly, it may need to be replaced or repaired.

  • Sensor check :
    Replace any faulty sensors that may affect the glow plug circuit.

Insight: Mechanical and Electrical Components Involved

Glow plugs

Glow plugs are electrical devices that preheat the air or fuel in the combustion chamber by heating it, making it easier to start the engine. A faulty glow plug can cause starting problems and erratic engine operation.

Power circuit

The glow plug power circuit consists of a relay, fuses, and wiring. An open or short circuit in this system can result in DTC code P0680. It is essential to ensure that the voltage and current are adequate for the glow plugs to function properly.

Engine Control Unit (ECU)

The engine control unit (ECU) controls the operation of the glow plugs by monitoring data from various sensors. A malfunction in this unit can prevent the engine from starting properly and the glow plugs from working properly.

Conclusions

DTC P0680 is a significant problem for diesel vehicles, especially in cold weather. Proper diagnosis and resolution of the problem are essential to ensure reliable starting and optimum engine performance. A thorough understanding of the components involved and systematic diagnosis can help auto repairers effectively resolve this fault, minimizing vehicle downtime and ensuring customer satisfaction.

Important
Not all OBD2 codes used by one manufacturer are used by other brands, and may not have the same meaning.
The information presented here is for informational purposes only. We are not responsible for any actions you take on your vehicle. If you have any concerns about repairing your vehicle, please contact your repair shop.