C1801 Diagnostic Trouble Code

C1801 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 C1801 diagnostic trouble code may include:

Rich or lean exhaust
Fuel pressure too low
Engine surge
Poor acceleration

Possible Causes :

Faulty IMRC actuator relay (if equipped)
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)

Repair Processes :

Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. 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. Look at the plug wires to make sure they are not burnt or laying on the exhaust.

Process Tips

Diagnostic trouble code C1801 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 C1801.

Fortunately, C1801 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C1801 Trouble Code For Specific Cars

C1801 Astra Utility Air Temperature External Sensor Circuit Short To Battery
C1801 Ford Skyliner Mirror Passenger Right Circuit Short To Battery
C1801 Toyota Bandeirante O2 Sensor Circuit High Voltage (Bank 2 Sensor 2)
C1801 Jaguar Xj-8 Seat Driver Occupied Input Circuit Failure
C1801 Studebaker Golden Hawk Lamp Turn Signal Right Circuit Open
C1801 Peugeot 4007 EGR Metering Orifice Restricted
C1801 Maserati 422 Transmission Fluid Pressure High