P0670 - GLOW PLUG CONTROL MODULE - CIRCUIT MALFUNCTION
Description of DTC code P0670
Diesel engines are not dependent on a compressed fuel mixture or an electrical ignition source for their proper operation. The compression of diesel engines is higher than gasoline engines.
Due to this high compression, the air in the cylinder can have a range of 600 degrees, which is the temperature needed to ignite the diesel fuel. As soon as the piston get to the top dead center of the cylinder, the high-pressure fuel is sprayed into the cylinder. Quickly, it burns when it meets the overheated air and the expanding gases push the piston down.
Keeping in mind that a diesel engine needs to be overheated to start the fuel if the engine is cold, it is difficult to overheat the air as heat is lost quickly. For this reason, the glow plug heats up for 10 seconds until the cylinder wall increases, thus, it allows the heat from compression to increase the amount of heat required for ignition.
In case the ECM (Engine Control Module) detects a problem in the control circuit of the GPCM (Glow Plug Control Module), the fault code P0670 ODB2 is set.
Symptoms of fault code P0670
- Check Engine
- Glow plug warning light on.
- In cold weather, the engine may not start.
- If the engine starts, there is a knocking sound until the engine reaches the required temperature.
- Excessive white smoke coming out of the exhaust.
Causes of OBD2 P0670
The reasons for setting the diagnostic code P0670 OBDII are:
- The spark plug relay may be stuck.
- A bad injection moment causes wear on the glow plug. This wear affects the glow plug.
- Defective glow plug.
Possible solutions of the DTC code P0670
To correct the problems with DTC code P0670 OBD2, you must do the following
- Make sure the battery is fully charged.
- Check all the cables, if they have defects, you must repair or replace them.
- With the aid of a voltmeter, measure the battery voltage to the main supply terminal of the glow plug relay. Then, turn the key to the ignition position and inspect the opposite terminal. If the voltage drops, you must change the relay.
- Check power to the power switch that goes to the relay with the switch in the on position.
- Check the spark plugs for any shorts in the circuit. Also, check the ground circuit. If you find problems in any of these, make the necessary repairs.