Lack of Power, Sluggishness, or Sponginess

WARNING: This page is about a different variant/trim than selected.

Checks	Action
DEFINITION: The engine delivers less than expected power. There is little or no increase in speed when partially applying the accelerator pedal.
Preliminary Checks	Refer to Symptoms - Engine Controls . Inspect for auxiliary fuel filters. Refer to Fuel Injection Line Routing Diagram for proper fuel filter locations. Aftermarket fuel filters may restrict fuel flow. Compare the vehicle with a similar unit. Ensure the vehicle has an actual problem. Compare the scan tool data at idle with the scan tool data list. Refer to Scan Tool Data List (Engine Control Module) or Scan Tool Data List (Glow Plug Control Module) . Remove the air filter and check for dirt, or for air ducts being plugged or leaking. Repair or replace as necessary. Inspect for a proper transmission operation. Inspect the engine oil level and quality.
Sensor Inspection	Observe the fuel rail pressure (FRP) sensor and the fuel pressure regulator commanded percent at idle. FRP should be near 40 MPa, and commanded percent should be near 40 percent. If the command is high, a fuel pressure or sensor issue exists. Inspect the crankshaft position (CKP) sensor reluctor wheel. Remove the CKP sensor and attempt to move the reluctor wheel front to back or side to side with a probe. If there is any movement the reluctor wheel retaining bolts are loose.
Fuel System Checks	Inspect the fuel supply to the fuel injection pump. Refer to Fuel System Diagnosis . Observe the actual vs desired fuel rail pressure with a scan tool, with the engine idling. Inspect the engine speed signal circuit for high resistance. If the engine control module (ECM) glow plug control module (GPCM) or a fuel injector has recently been replaced, it may be necessary to confirm the fuel injector flow rate values. Refer to Fuel Injector Flow Rate Programming . Inspect for restricted or plugged fuel injectors. Refer to Fuel Injector Balance Test with Tech 2 (Manual Transmission) or Fuel Injector Balance Test with Tech 2 (Automatic Transmission) .
Exhaust System Checks	Inspect the exhaust system for a possible restriction. Refer to Restricted Exhaust .
Air Intake System Checks	Inspect for an air leak or restriction in the air inlet ducts or the intake manifold. Refer to DTC P0234 . Inspect for an air leak or restriction in the charge air cooler with a J 46091 Charge Air Cooler Tester. See Special Tools . Inspect for a worn or damaged turbo charger turbine wheel, shaft or compressor wheel. Inspect for a skewed mass air flow (MAF) sensor. Refer to Diagnostic Aids in DTC P0101 .
Engine Mechanical Check	Inspect the engine for the following: Low compression Improper valve timing Improper or worn camshaft Refer to Engine Compression Test .
Additional Checks	Inspect the control module grounds for being clean, tight, and in their proper location. Inspect the torque converter clutch (TCC) operation. Inspect the air conditioning system for proper operation. Refer to Air Conditioning (A/C) System Performance Test (Diesel Engine) or Air Conditioning (A/C) System Performance Test (Gas Engine w/ Electric Cooling Fan ) or Air Conditioning (A/C) System Performance Test (Gas Engine w/Engine Driven Fan) . Inspect the generator output voltage. Refer to Charging System Test .