C1540 Diagnostic Trouble Code

C1540 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 C1540 diagnostic trouble code may include:

Blown fuse (if applicable)
Engine surge
Reduction in engine performance, especially at low RPM levels
Rich or lean exhaust

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.
Dirty air cleaner element Damaged DPF

Repair Processes :

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. 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. 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 C1540 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 C1540.

Fortunately, C1540 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C1540 Trouble Code For Specific Cars

C1540 Ford S-max 2 Mirror Passenger Right/Left Motor Stalled
C1540 Mazda Cu-x Transmission Transfer Case Disengaged Solenoid Short to Battery
C1540 Toyota Prius 4 Park Brake Actuator Assembly Switch Released Circuit Failure
C1540 Caterham Super 7 Door Handle Right Front Circuit Open
C1540 Honda Today Reverse incorrect gear ratio
C1540 Subaru Vivio Low Coolant Lamp Output Circuit Short to Battery
C1540 Studebaker Daytona Lamp Turn Signal Right Circuit Failure