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.
Clearing Codes
Only Continuous Memory (history) codes are stored in ECA memory. Neither On-Demand nor Engine Running codes are stored so do not have to be cleared.
To clear Continuous codes from ECA memory, run the KOEO Self-Test. See STEP 2.0: VEHICLE PREP & EQUIPMENT HOOKUP for equipment hookup, and STEP 3.0: PERFORM KOEO SELF-TEST to start the test. When codes begin to be displayed (any codes), deactivate the self-test:
- STAR Tester: Unlatch the center button (up position).
- VOM: Remove the jumper wire from between Self-Test Input (STI) single terminal pigtail and the Signal Return terminal of the large Self-Test connector.
- "CHECK ENGINE" or "SERVICE ENGINE SOON" Light (MIL): Remove the jumper wire from between Self-Test Input (STI) single terminal pigtail and the Signal Return terminal of the large Self-Test connector.
- Scan Tool: Follow manufacturer's recommendations.
The Continuous codes are now erased from memory. Note that if a fault is still present, a code will be immediately reset into the ECA memory.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.