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.
Readiness Code Description
Diagnostics are performed at regular intervals during normal vehicle operation. After repairing an emissions related system, a readiness code is generated by road testing the vehicle.
If a malfunction is recognized during the drive cycle, it will be stored in the DTC memory.
The OBD drive cycle operation will be monitored with a hand held diagnostic tool. Consult the manufacturer's instruction for correct tool operation.
The readiness code is erased every time the DTC memory is erased or any time the battery is disconnected. If the DTC memory has been erased or the battery is disconnected, a new readiness code must be generated.
Only erase the DTC memory if a DTC has been stored.
General Recommendations
Most monitors will complete easier and quicker using a "steady-foot" and "smooth" acceleration during the drive cycle operation, cruise, and acceleration modes.
Test requirements
- Engine coolant temperature 25° C (77° F) Minimum.
When performing the drive cycle operation, pay strict attention to driving conditions and please observe and obey all posted speed limits. Failure to follow these instructions may result in personal injury or possible death.
Drive Cycle Procedure
-- Connect the scan tool.
-- Start engine and increase speed to 2200 RPM, by referring to tachometer.
At engine speed of at least 2200 RPM:
-- Release accelerator pedal and allow engine to return to idle (approx. 900 RPM).
-- Stop engine and wait approx. 10 seconds.
-- Start engine and increase speed to 2200 RPM, by referring to tachometer.
At engine speed of at least 2200 RPM:
-- Release accelerator pedal and allow engine to return to idle (approx. 900 RPM).
-- Check the status of the readiness code.
Depending on the scan tool used. The readiness code status may be displayed as complete, passed or OK.
-- If any engine monitor fails the drive cycle test. Repeat the drive cycle test until all engine monitors have successfully run through and passed.
If the drive cycle operation fails again.
-- Check the DTC memory for stored DTC's DIAGNOSTIC MODE 03 - READ DTC MEMORY .
Repair the vehicle if necessary.
-- Repeat the drive cycle operation until all engine monitors have successfully run through and passed.
-- Remove the scan tool and switch the ignition off.
End of Procedure.
NO RELATED
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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.