C2859 Diagnostic Trouble Code

C2859 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 C2859 diagnostic trouble code may include:

Poor fuel economy
Possible spark knock (detonation / pre-ignition)
Misfire
Rich or lean exhaust

Possible Causes :

The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Fuel with a large percentage of sulfur will clog the DPF quickly
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.

Repair Processes :

Find out what kind of system you have and verify that voltage to the fuel level sensor is present at the fuel pump wiring harness. 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. If you find a related TSB, the information will often help in diagnosing the code in question as TSBs are crested from many thousands of repairs.

Process Tips

Diagnostic trouble code C2859 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 C2859.

Fortunately, C2859 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C2859 Trouble Code For Specific Cars

C2859 Studebaker Lark Lamp Turn Signal Right Circuit Short To Ground
C2859 Reliant Kitten Gate Select Actuator Circuit High
C2859 Pierce-arrow 8 Engine Oil Temperature Sensor Range/Performance
C2859 Italdesign Medusa SCP (J1850) Lack of Acknowledgment for Primary Id
C2859 Brutsch Avolette Cruise Control Off Signal Malfunction
C2859 Puma Gt Fuel Temperature Sensor #1 Circuit Short to Battery
C2859 Ford Freestar Mirror Driver Horizontal Feedback Potentiometer Circuit Open