C0689 Diagnostic Trouble Code

C0689 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 C0689 diagnostic trouble code may include:

Possible spark knock (detonation / pre-ignition)
Poor fuel economy
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
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Defective ECU strategies or components will prevent proper regeneration

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. 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. If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for.

Process Tips

Diagnostic trouble code C0689 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 C0689.

Fortunately, C0689 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0689 Trouble Code For Specific Cars

C0689 Ducati Monster 797 Illuminated Entry Input Short Circuit To Battery
C0689 Fiat 508 Lamp Backup Switch Input Circuit Short To Battery
C0689 Oldsmobile F-85 Cylinder 9 Injector Circuit Low
C0689 Westfield Zei
C0689 Singer 2-litre Internal Control Module ROM Error (Module Identification Defined by SAE J1979)
C0689 Berkeley B Booster Pedal Force switch circuit Failure
C0689 Vauxhall Prince Pressure Control Solenoid C