Sensor/System Checks

2001 Chevrolet Chevy Express G2500, Van Passenger Extended, 5.0 MSECTION Sensor/System Checks
WARNING: This page is about a different car, the 2003 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
  • Check the Engine Coolant Temperature (ECT) sensor for being shifted in value. Install the scan tool and compare the displayed engine coolant temperature with the intake air temperature on a cold engine. Check the resistance of the ECT sensor if the engine coolant temperature is not within 5Β°F of Intake Air Temperature (IAT). See TEMPERATURE VS RESISTANCEΒ  table. If the ECT sensor resistance is not within specification, see DTC P0117: ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT LOW VOLTAGE OR DTC P0118: ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT HIGH VOLTAGE under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - 4.0L AURORA article.
  • Check the Mass Airflow (MAF) sensor and connections.
  • Check the operation of the Idle Air Control (IAC) valve. See IDLE AIR CONTROL SYSTEM DIAGNOSIS under IDLE CONTROL SYSTEMS in SYSTEM & COMPONENT TESTING - 4.0L AURORA article.
  • Using the scan tool, monitor the Throttle Position (TP) sensor voltage. The TP sensor voltage should be less than 0.9 volt with a closed throttle. If the TP sensor voltage is more than 0.9 volt, inspect the throttle body and accelerator cables for binding.
  • Check for the proper operation of the Exhaust Gas Recirculation (EGR) system. See EXHAUST GAS RECIRCULATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - 4.0L AURORA article.
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.