C2690 Diagnostic Trouble Code

C2690 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 C2690 diagnostic trouble code may include:

Fuel pressure too low
Rich or lean exhaust
Diminished fuel efficiency
Reduction in engine performance, especially at low RPM levels

Possible Causes :

A faulty oxygen sensor. This will set a code in itself, however, a faulty oxygen sensor does not automatically condemn the sensor. The code just means that the sensor signal was not within specifications. An air leak or any of the above will cause an erroneous signal. There is a multitude of O2 codes relating to O2 performance which gives a clue to the problematic area.
Some aftermarket accessories and performance modifications
Faulty IMRC actuator/sensor

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. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. Pull the connectors apart and carefully look at the terminals (the metal parts) inside the connectors. 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 C2690 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 C2690.

Fortunately, C2690 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C2690 Trouble Code For Specific Cars

C2690 Bristol 400 Cooling Fan 3 Control Circuit Malfunction
C2690 Alvis Ta21 Air Pressure Low Circuit Short to Gnd
C2690 Calthorpe 12 Door Ajar Circuit Open
C2690 Rochet-schneider 30 Hydraulic Pressure Sensor Circuit Low Input
C2690 Hotchkiss 3.5-litre Ride Control LF Shock Actuator Circuit Failure
C2690 Revere M HO2S Insufficient Switching Sensor 1
C2690 Hillman Hunter Passenger's Seatbelt Tension Reducer Circuit Short to Ground