C2191 Diagnostic Trouble Code

C2191 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 C2191 diagnostic trouble code may include:

Lack of power
Faulty O2 Sensor
Poor acceleration
Hesitation upon acceleration

Possible Causes :

Some aftermarket accessories and performance modifications
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.
Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.

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.

Process Tips

Diagnostic trouble code C2191 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 C2191.

Fortunately, C2191 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C2191 Trouble Code For Specific Cars

C2191 Vaz Lada PRNDL Reverse Input Circuit Failure
C2191 Honda Acura El Pressure Control Solenoid B Control Circuit Low
C2191 Mercury Montclair Air Suspension Rear Height Sensor Low Signal Circuit Failure
C2191 Toyota Opa Overdrive Band Failed Off
C2191 Darracq Type N Heated Windshield Input Short to Ground
C2191 Volvo Hatric SCP (J1850) Invalid or Missing Data for Engine Sensors
C2191 Elva Mk Injection Pump Fuel Metering Control "A" Malfunction (Cam/Rotor/Injector)