C1812 Diagnostic Trouble Code

C1812 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 C1812 diagnostic trouble code may include:

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

Possible Causes :

Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.

Repair Processes :

Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data.

Process Tips

Diagnostic trouble code C1812 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 C1812.

Fortunately, C1812 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C1812 Trouble Code For Specific Cars

C1812 Ballot 2-litre B Camshaft Position - Actuator Circuit (Bank1)
C1812 Mitsubishi Dion Autolamp Delay Circuit Failure
C1812 Dodge Colt Ignition Coil D Primary/Secondary Circuit Malfunction
C1812 Porsche 906 Front Wiper Select Switch "A" Short to Ground
C1812 Holden Clubsport Pedal Position Sensor B Circuit Intermittent
C1812 Panhard Cd Driver Power Window Down Circuit Short To Ground
C1812 Simca 1200 Intake Manifold Runner Control (Bank 2) Stuck Open