P1240 Diagnostic Trouble Code

P1240 is a kind of OBD-II Diagnostic P-Powertrain 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 P1240 diagnostic trouble code may include:

Engine surge
Blown fuse (if applicable)
Lack of power
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

Possible Causes :

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

Repair Processes :

You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data. 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 P1240 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 P1240.

Fortunately, P1240 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P1240 Trouble Code For Specific Cars

P1240 Packard Eight Driver Door Ajar Circuit Open
P1240 Renault Super HO2S Heater Control Circuit (Bank 1 Sensor 1)
P1240 Daimler One-o-four Heated Backlite Relay Circuit Failure
P1240 Diva 10f IAC Monitor Disabled by PSP Switch Failed On
P1240 Hyundai Dynasty SCP (J1850) Invalid Data from REM
P1240 Ferrari 488 Intake Manifold Runner Control (Bank 2) Stuck Closed
P1240 Lada 1600 Shift Solenoid A Control Circuit High