C0709 Diagnostic Trouble Code

C0709 is a kind of OBD-II Diagnostic C-Chassis Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a C0709 diagnostic trouble code may include:

Rich or lean exhaust
Fuel pressure too low
Engine surge
The engine oil will exhibit dilution from the ECUs attempts to increase engine temperature. Some vehicles advance the fuel injection timing slightly after top center to afterburn a small amount of fuel to increase exhaust temperatures. Some of this fuel enters the crankcase. When the ECU determines the necessity to regenerate the DPF, the service life of the oil be shortened significantly

Possible Causes :

Defective ECU strategies or components will prevent proper regeneration
The Mass Airflow sensor is a hot wire that senses the volume of air entering the intake manifold. The computer uses this information to control fuel mixture.
Faulty IMRC actuator relay (if equipped)

Repair Processes :

With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground. Check to make sure they are not burnt or corroded. If in doubt, get some Electrical Contact cleaner at any parts store if cleaning of the terminals is needed. Oxygen sensors signal the engine management computer the amount of oxygen present in the exhaust, which is used in determining and controlling the fuel ratio.

Process Tips

Diagnostic trouble code C0709 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before C0709.

Fortunately, C0709 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0709 Trouble Code For Specific Cars

C0709 Hyundai H100 SCP (J1850) Invalid or Missing Data for Brakes
C0709 Saturn Aura IMCC Circuit Malfunction, Bank B
C0709 Kia Carnival Seat Recline Forward/Backward Potentiometer Feedback Circuit Open
C0709 Bmw Coupe Climate Control Temperature Differential Circuit Short To Battery
C0709 Daihatsu Mira Generator Lamp "L" Control Circuit Malfunction
C0709 Buick Special Damper LF Circuit Failure
C0709 Nissan 180 Child Seat Detection Circuit Short to Ground