The engine output is less than expected. The engine speed hardly increases or does not increase at all even when the accelerator pedal is depressed.
Perform the Diagnostic system check - engine controls.
Perform the Fuel supply pump functional inspection.
Compare the vehicle with a similar vehicle. Check if any problem exists in the vehicle.
Remove the air cleaner and inspect for contamination, collapsing in the air duct, or any condition that restricts the flow.
Check whether the tire size was changed.
Check if excessively heavy loads are carried.
Inspect for clutch slip.
Inspect for brake drag.
Inspect whether the transmission shift pattern and the down shift operation are normal.
Inspect the fuel quality.
Inspect the engine oil level and oil quality.
Make sure the Vehicle Speed parameter matches the value in the vehicle speedometer with a scan tool.
Ensure that the ground of the ECM is free of dirt and is fixed securely in the correct position.
Verify the Injector ID Code of each cylinder.
Check the scan tool data list.
Check for related Service Bulletins.
Compare the Engine Coolant Temperature (ECT), Intake Air Temperature (IAT), and Fuel Temperature parameters while the engine is cold. If the difference between the temperature values is 5°C {9°F} or more when the engine is cold, inspect for high resistance in each circuit and for a sensor malfunction.
{When the ignition switch is turned ON, the MAF sensor is heated, and as a result, the IAT shows a higher value than the normal intake air temperature.}
Observe the Mass Air Flow (MAF) parameter on the scan tool, and check for a MAF sensor malfunction or slow reaction.
Observe the Fuel Rail Pressure (FRP) Sensor parameter on the scan tool. It is normal if the Fuel Rail Pressure (FRP) Sensor parameter shows approximately 20 MPa or more when the ignition switch is turned ON without starting the engine after the engine operation is stopped. If not, inspect for high resistance in each circuit and for a sensor malfunction.
Observe the Fuel Rail Pressure (FRP) parameter and Desired Fuel Rail Pressure (FRP) parameter while fully depressing the accelerator pedal from idling with the vehicle in neutral. The difference between the displays should always be within 5 MPa {725 psi}.
Observe the Accelerator Pedal Position (APP) parameter. It is normal if the Accelerator Pedal Position (APP) parameter changes linearly from 0 to 100% according to the accelerator pedal operation.
Observe the Boost Pressure parameter and Barometric Pressure (BARO) parameter when the ignition switch is ON and the engine is OFF. It is normal if the difference between both parameters is within 7.0 kPa {1.0 psi}.
Inspect for air in the fuel system.
Inspect for water in the fuel.
Inspect whether the fuel is frozen.
Inspect whether the fuel filter warning light illuminates intermittently or frequently.
Inspect the fuel filter for clogging.
Inspect for external fuel leakage and excessive engine oil.
Inspect for fuel leakage from the injector.
Inspect for collapsing, twisting, improper tightening, cracking, or clogging in the fuel system between the fuel tank and the fuel supply pump.
Inspect the vent valve and hose of the fuel tank for clogging.
{The piping may be clogged due to foreign material from the fuel tank entering the fuel system.}
Inspect the operation of the fuel supply pump.
{The fuel supply pump must be timed with the engine, and the adjusted value should be learned by the ECM.}
Perform Injector Cutoff with a scan tool.
Observe the Fuel Compensation parameter for each cylinder on the scan tool while idling.
Inspect the air cleaner, air intake duct, and intercooler for clogging, holes, or leakage.
Inspect for any condition that restricts flow within the turbocharger intake duct.
Inspect the intake throttle valve for sticking.
Inspect the inlet manifold for clogging or air leakage.
Inspect the MAF sensor for dirt or damage.
Perform the Variable Swirl Valve with a scan tool. Inspect the diaphragm valve operation when the diaphragm valve is commanded ON/OFF.
Inspect the turbocharger turbine wheel, shaft, or compressor wheel for wear or damage.
Inspect the VGS actuator operation.
Inspect whether the exhaust system flow is restricted.
Inspect the compression pressure of the engine.
Inspect the valve clearance.
Inspect the valve spring for breakage and fatigue.
Inspect the camshaft for wear.
Inspect whether the EGR system is operating properly.
Perform the EGR control system check.
Observe the Neutral Switch parameter on the scan tool.
Inspect whether the engine has overheated.
Inspect the operation of the A/C.
Inspect the operation of the torque converter clutch. (Automatic transmission models)