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.
2006 Chevrolet Optra LS, AutomaticFACTORY OEM SERVICE PROCEDURE
Circuit/System Testing
- Ignition OFF, disconnect the harness connector of the crankshaft position (CKP) sensor.
- Ignition ON, verify that 1.5-2.0 volts is available on the signal circuit and the low reference circuit of the CKP sensor.
- If less than 1.5 volts, test the applicable circuit for a short to ground or an open/high resistance. If the circuits/connections test normal, replace the ECM.
- If more than 2.0 volts, test the applicable circuit for a short to voltage. If the circuits/connections test normal, replace the ECM.
- If all circuits/connections test normal, test or replace the CKP sensor.
IMPORTANT:
If the CKP sensor lead is damaged in any way, replace the CKP sensor.
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.