Tesla Model 3 Hard Start / No Start When Warm
The vehicle cranks but fails to start when the engine is warm. This is unusual for an electric vehicle, but if referring to a hybrid or range extender, common causes include fuel vapor lock, failing coolant temperature sensor, or weak 12V battery. For a pure EV, 'cranking' is not typical; the issue may be a high-voltage battery or contactor fault.
Diagnosis Details
Possible Causes
12V battery weak or failing – common cause of no-start in EVs, especially when warm due to increased electrical load.
High-voltage battery contactor stuck or failing – prevents power flow to the motor.
Coolant temperature sensor sending incorrect signal to BMS, causing start inhibition when warm.
Related OBD-II Codes
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What You Should Do
Check 12V battery voltage and condition; replace if below 12.4V.
Inspect high-voltage contactor operation via diagnostic tool.
Verify coolant temperature sensor readings with a scan tool.
If no codes, perform a full system reset by disconnecting 12V battery for 5 minutes.
Related Repairs
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Disclaimer: This AI-generated diagnosis is for informational reference only. Always consult a qualified mechanic for an in-person inspection. AutOwner is not responsible for decisions made based on this information.
