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.
2011 Lexus IS 350 Base, AWDFACTORY OEM SERVICE PROCEDURE
DTC P0604: Internal Control Module Random Access Memory (RAM) Error: Procedure
- CHECK DTC
- Clear DTC. Refer to DTC CHECK / CLEAR .
- Turn the engine switch off.
- Disconnect the battery negative terminal and wait for 1 minutes.
- Connect the battery negative terminal.
- Turn the engine switch off.
- Check DTC.
OK
P0604 is not present.
NG → See step 2
OK → CHECK FOR INTERMITTENT PROBLEMS
- REPLACE ECM. Refer to REMOVAL
Factory Service Tools
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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.