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 Mass Airflow (MAF) sensor and connections.
  • Check the Engine Coolant Temperature (ECT) sensor for being shifted in value. Connect the scan tool and compare the ECT with the Intake Air Temperature (IAT) sensor on a cold engine. The ECT and IAT should be within 5Β°F of each other. Check the resistance of the ECT sensor if the temperature is out of range with the IAT sensor. See TEMPERATURE VS RESISTANCEΒ  table for specifications.
  • Check Throttle Position (TP) sensor and connections. See DTC P0121: THROTTLE POSITION SENSOR CIRCUIT INSUFFICIENT ACTIVITY under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - 4.0L AURORA article.
  • Check for throttle body tampering, excessive deposits, or damage.
  • Check the Exhaust Gas Recirculation (EGR) system for proper operation. See EXHAUST GAS RECIRCULATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - 4.0L AURORA article.
TEMPERATURE VS RESISTANCE

Temperature - Β°F (Β°C) (1) Ohms
302 (150) 47
266 (130) 77
230 (110) 132
194 (90) 241
158 (70) 467
122 (50) 973
104 (40) 1459
86 (30) 2238
68 (20) 3520
50 (10) 5670
32 (0) 9420
14 (-10) 16,180
-4 (-20) 28,680
-40 (-40) 100,700
(1) Values are approximate.
RENDER: 1.0x

NO RELATED

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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.