FUEL INJECTION AMOUNT LEARNING [SKYACTIV-D 2.2]
id0180q1000700
Purpose of Adoption
• To realize stable fuel injection, deviation in the fuel amount due to deterioration over time is corrected.
Service Point
• After replacing the PCM, fuel indicator, airflow sensor, timing chain, or DPF, fuel injection amount learning is required. In addition, fuel injection amount learning is required in scheduled inspection/service.
• For the fuel injection learning, one method uses the M-MDS and the other method is performed by short circuiting the check connector terminal as indicated below.
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<Fuel injection amount learning procedure>
1. Switch the ignition ON.
2. Start the engine and let it warms up.
3. Ground the tester terminal to the body 5 times within 5 seconds.
4. Verify that the glow indicator light is illuminated (When learning is completed, the glow indicator light flashes numerous times).
• Depending on whether i-ELOOP is equipped or not, the engine speed behavior varies slightly during fuel amount learning, but this does not indicate a malfunction.
Common Inquiry
• The fuel injection amount learning, which is performed automatically during idling, is performed while i-stop is not operating (congested traffic, i-stop inhibit switch is ON) because, in principle, i-stop takes precedence.
• However, if the drive distance without learning reaches its limit, the fuel injection amount learning takes precedence, and when the vehicle decelerates to 10 km/h {6.2 mph} or less, the i-stop lamp turns off and learning is performed when the engine idles.
• If the learning value for very small injection amounts such as pilot, pre-injection is off by a large amount, problems such poor as idling, poor ignition, air suction, surge, knocking, and poor i-stop engine restarting could occur. For this reason, scheduled maintenance (12-month inspection) and implementation of fuel injection amount learning while the vehicle is in the shop is necessary.
• During idling after driving a certain distance, auto learning is performed, but if the learning conditions are not correct (low ambient/engine coolant temperature) and depending on how the customer drives the vehicle (no idling), automatic learning may not take place at all. For this reason, scheduled maintenance (12-month inspection) and implementation of fuel injection amount learning while the vehicle is in the shop is necessary.
• The engine sound changes slightly during fuel injection amount learning, but this does not indicate a malfunction.
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