Mixture adaptive correction

I - PRINCIPLE

In closed-loop phase, mixture control corrects injection time so as to obtain a mixture as close as possible to richness 1. The mixture correction value PR138 is close to 50%, with stops at 0% and 100%.

Adaptive mixture corrections PR143 and PR144 shift the injection map to re-centre mixture control on 50%.

Adaptive corrections take 50% as the average value after ECU reset (memory erase) and have stop values.

K4J or K4M

Adaptive deactivation during prolonged idle with warm engine

If the coolant temperature is above 90 °C during idle for more than 10 minutes (K4M engine) and 1 minute (K4J engine), the adaptives are frozen until the end of idle. Following this test, the corrections are operational.

Continue the test by driving under normal, varied, smooth driving conditions for 5 to 10 km. After this test, read the adaptive values. They started at 50%, so they should have changed.

Otherwise, repeat the readings, taking care to respect the test conditions.

Conditions for learning the adaptive fuel richness correction:

• engine warm: coolant temperature above 80 C,
• do not exceed an engine speed of 4640 rpm,
• disconnect the fuel vapour canister solenoid valve or plug the supply hose on the engine.

F4R

Adaptive deactivation during prolonged idle with warm engine

If the coolant temperature is above 80 C during idle for more than 1 minute, the adaptive values are frozen until the end of idle. After this test, the corrections are operational. Continue the test by driving under normal, varied, smooth driving conditions for 5 to 10 km. After this test, read the adaptive values. They started at 50%, so they should have changed. Otherwise, repeat the readings, taking care to respect the test conditions.

Conditions for learning the adaptive fuel richness correction:

• engine warm: coolant temperature above 80 C,
• do not exceed an engine speed of 4512 rpm,
• disconnect the fuel vapour canister solenoid valve or plug the supply hose on the engine.

Pressure zones to sweep during the test

K4J or K4M

There are five pressure zones to sweep during driving. These zones are defined by the following calibrations:

F4R

There are five pressure zones to sweep during driving. These zones are defined by the following calibrations:

II - INTERPRETING VALUES RECORDED DURING A ROAD TEST

In the case of a fuel shortage (dirty injectors, fuel pressure and flow too low, etc.), the richness control increases to obtain a richness closest to 1, and the adaptive richness corrections increase until the richness correction oscillates back around 50%.

In the case of excess fuel, the reasoning is reversed.