LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Hummer >> 2010 >> H3 Base, Standard >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls And Fuel - 3.7L - DTC P0335 To DTC P1381 >> DTC P1174 >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing

  1. Read and record the Freeze Frame/Failure Records data taking note of the speed and load at which the DTC set.
  2. Diagnose any other DTCs that are set. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
  3. With the engine idling and the transmission in the Park or Neutral position, observe the manifold absolute pressure (MAP) sensor parameter. The MAP sensor parameter should be between 19-42 kPa.
    • If the MAP sensor parameter is not between 19-42 kPa, refer to DTC P0106 .
  4. Inspect the air induction system for modified, damaged, leaking, or restricted components.
  5. Inspect the crankcase ventilation system for improper operation. Refer to Crankcase Ventilation System Inspection/Description .
  6. Inspect the vacuum hoses for splits, kinks, and improper connections.
  7. Inspect for vacuum leaks at the intake manifold, the throttle body, and the injector O-rings.
  8. Test for a restricted, damaged, leaking, or modified exhaust system from the catalytic converter forward. Refer to Symptoms - Engine Exhaust .
  9. Test the fuel injectors for improper operation. Refer to Fuel Injector Diagnosis (W/J39021 or W/Tech 2) or Fuel Injector Diagnosis (W/CH47976) .
  10. Test for fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
  11. Test for excessive fuel in the crankcase due to leaking injectors.
  12. Test the ignition system for improper operation. Refer to Electronic Ignition System Diagnosis .
  13. Test the engine for any mechanical conditions such as sticking valves, lifters, etc., which could alter the flow into the combustion chamber. Refer to Symptoms - Engine Mechanical .
scientia non olet · About LEMON Manuals