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.
2001 Mercedes Benz ML430FACTORY OEM SERVICE PROCEDURE
DTC Description
- Fault Memory & Actuation Of MIL - After 2 consecutive driving cycles with fault.
- Frequency Of Testing - Continuous.
- Checked Signal Or Status - Correction value exceeded or cycle duration too long.
- Limit Values Of Correction Value - Approximately plus or minus 1.2 seconds.
- Period Of Limit Value - More than 5 seconds (average value from more than 15 measurements).
- Duration Of Test - Up to 190 seconds.
- Test Conditions - Engine speed approximately 1000-2000 RPM, engine load approximately 15-50 percent, TWC temperature more than 716°F (380°C), Lambda control enabled, no fault with TWC effect, and no fault with O2 sensor heating.
NOTE:
The period of the O2 sensor before TWC is too long; O2 sensor after TWC does not continue to be monitored. Correction value of O2 sensor before TWC exceeded; O2 sensor after TWC continues to be monitored. If faults for the O2 sensor before and after TWC are recognized at the same time; usually only the O2 sensor after the TWC is defective.
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.