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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 353 (ENGINE CONTROLS - TROUBLE SHOOTING - NO CODES - 2.2L Bi-Fuel) >> Symptoms >> Hard Start >> Sensor Checks

Sensor Checks

WARNING: This page is about a different car, the 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check the ECT sensor for proper operation by performing the following:
    • Allow the engine temperature to reach ambient air temperature by leaving the engine OFF for several hours, overnight for most accurate results.
    • Turn the ignition switch to RUN position while leaving the engine OFF.
    • Using a scan tool, compare the Engine Coolant Temperature (ECT) and Intake Air Temperature (IAT) sensors displayed temperature. The sensors should be within 5°F (3°C) of each other.
    • Replace the ECT sensor or repair the ECT sensor circuit if the ECT is not near the expected value.
  2. Check the Throttle Position (TP) sensor for proper operation. With the throttle blade fully at rest the monitored TP sensor voltage on a scan tool should be less than 0.85 volt. If the TP sensor is not near the expected voltage check for the following conditions:
    • A faulty TP sensor.
    • A faulty TP sensor circuit.
    • A sticking throttle shaft or linkage/cable assembly.
  3. Check for proper operation of the Crankshaft Position (CKP) sensor.
  4. Check for proper operation of the MAP sensor (if equipped).