Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1934 (ENGINE CONTROLS AND FUEL - 3.6L (LCS) - DTC P0008 TO DTC P0193)DTC P0119CIRCUIT/SYSTEM TESTING
2003 Chevrolet TrailBlazer 4.2 S, 4WD
Circuit/System Testing
2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Circuit/System Testing
WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description .
- Ignition ON, verify the scan tool hood position parameter displays Open.
- If the hood position does not display Open, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Ignition OFF, disconnect the engine coolant temperature (ECT) sensor.
- Ignition ON, verify that the scan tool ECT sensor parameter is at -40Β°C (-40Β°F).
- If warmer than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
- Ignition OFF, remove the fuse that supplies B+ to circuit terminal X2-56 of the ECM.
- Test for less than 5 Ξ© between the low reference circuit terminal 2 and ground.
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
- Install the fuse that supplies B+ to circuit terminal X2-56 of the ECM.
- Ignition ON, connect a 3 A fused jumper wire between the signal circuit terminal 1 and ground. Verify the scan tool ECT sensor parameter is greater than 142Β°C (288Β°F).
- If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
- If all circuits test normal, test or replace the ECT sensor.
CAUTION:
Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw.
NOTE:
If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage and the sensor may be damaged.
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.