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Fuel Corrections Idle Load Trim


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Hello to all

Within the menu fuel - fuel corrections - Idle load trims.

Air con trim - does not work.

Drive trim - works without being set no DI park - neutral.

Eng Fan trim - works when the fans are on.

Setup used:

DI 2 - Air con request

Pullup - off

On - High

Aux 10 - Air con clutch

Polarity - low

Cluch Release - TP

Sw off value - 85

Cluctch delay - 5

The air conditioning system works normally, so does not work adjustment trim air con.

ECU data and firmware.

Main Code Firmware Version: 4.9.9.

Boot Code Firmware Version: 1.4

Map Calibration: 65533

Support Board Revision: 1.2

Ecu Type: V88 vipec

ECU Serial Number: 4829

Link Id: 1800

Min spec ECU: 4:90

I thank the answer my doubts.


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the drive trim will always work, even without a neutral park or gear switch being employed.

You should leave this setting turned off, to 0 if you have no DI to activate it, otherwise you will always have the trim amount selected active to the fuel Main Table.

Can you post your PCL file regarding the aircon so I can test the function of the inputs , outputs etc on my simulator.

Otherwise you can check the status of everything related in the runtimes list hit F12, Look at digital inputs to check the A/C request is functioning, check aux outputs to see if the clutch output is activating etc.



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I have kind of a similar question. When my A/C kicks on, my AFR goes super rich. 10.0-10.4 to 1. I have all three of the mentioned fields set to 0.00 ms. It doesn't make a difference. Is there another table? or can I go negative with the trims?

Hmm...Apparently it will let me enter a negative value. Haven't tried it on the car yet though.



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Hi, you must also remember with the different loads applied that the ignition timing and main fuel table values and idle speed tables etc will also change as the load varies with the differing conditions,

The trims are only part of the equation.



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My car runs at idle with the a / f 14.7:1 perfect.

When you turn on the air conditioning the mixture goes to 17:1 and this time the adjustment of Trim Air con has to make this correction. However, this setting does not work can range from -2.00 ms to +2.00 ms, the A / F does not change.

But if I do the same thing in Eng Fan trim function and the engine fan is turned on the A / F change at the same time for more (0ms to 2.00ms +) A / F goes to 12:1 or less (for 0.00ms. - 2:00 ms) A / F goes to 17:1.


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If you can post you map that would be great as we can check this on the bench relatively easy.

But as the load will have changed you will have moved to a slightly different area of the MAP and you might require some adjustment of the map to compensate.

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I have given this a run on the bench and the trim is working as expected.

The trim is applied only when the Aux out set for AC clutch is active. This does have a delay after the AC request state changes.

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Looking inside the menu ​​run time values - Fuel trims -

Air con Fuel trim (ms) - 0.00 (this parameter does not obey the command with the air conditioner running.

Eng Fan trim (ms)-o, o (varies between -2ms to +2 ms (when the fan is running) - Engine Temp 99 degrees

Drive Fuel Trim (ms) -0.00 (varies between -2ms to +2 ms all the time that the engine works)

Looking inside the run time values menu - Digital - DI2 - Air con request - ACTIVE.

Looking inside the run time values menu - Auxiliary - 10 Aux Air-con clutch - ON.

But Idle load Trins - Air Con Trim does not work.

Was that a defect or problem the ECU firmware.

Was that a defect or problem the ECU.


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Good morning Augusto,

Simon is away today. Can you please post a PCLog of your vehicle at idle and then activate the air conditioning. I will look in the log to try and identify why your setup has a problem and why Simon had it working here when he tested.


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Hi Scott

I'm sending the log request, please look at the changes Fuel Trim.

Engine fan trim - Engine fan - on - ok.

Fuel trim Drive - ok.

Air con Fuel trim - not working - DI2 - Active - Aux 10 - on.

I can not send this log message appears.

The extension llg is not allowed.

Sorry my english.


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