[ferbmw]

Hi Gents,

I am having a problem with a RAV4 2018 4WD, engine 2.5L, automatic gearbox.

The issue is with the idle speed when in Drive and press the brake pedal. In that circumstance the idle speed drops about 150 rpm , from 770 to 620 rpm aprox. ( it does not happen if the manual brake is applied )

I have cleaned the throttle body, have checked the brake booster for no leaks, vacuum lines, and the rear brake lights circuit ( presuming for a short circuit ), with no success.

It does not happen with headlights on or when the day/night sensor turns lights on or with A/C on, in other words the car compensates the extra charge from these consumers.
Only happens when lights are off and no other electrical consumers are on.

Any ideas? Programming issue? Is it normal? This is not something I cannot live with, but the car in these circumstances shakes a little bit.

Thanks for your help in advance

 

[Asantoyo4]

Vacuum leak from booster is my guess. Especially if only happens when brakes are applied.

Good luck finding the issue and Happy Holidays

 

[ferbmw]

Vacuum leak from booster is my guess. Especially if only happens when brakes are applied.

Good luck finding the issue and Happy Holidays

Hi, thanks for your answer.
Brake Booster has been checked and has no leaks. When you press brake pedal in neutral or in parking , there is no drop in idle speed.
When you press brake pedal in drive but you manually press the brake pedal switch ( wich is located below the dashboard ), there is no drop in idle speed either, so I relate the problem with the signal sent by the switch to the ECUs.

Regards

 

[Asantoyo4]

Perhaps something is drawing a bunch of amps when the rear brake lights turn on?

 

[Naj]

I am facing exact same issue in my Rav4 2016. Where you able to solve this.? Sorry, I know this thread is old. But hop i find a solution.

 

[Leorav4]

I would not worry about it. All ravs do that. My does it 12 years already, just turn on AC for a short time.

 

[Naj]

Ok Thank you. But during idle in drive and reverse, rpm lowers to 500 and vibrates a lot. New all 4 mounts, new spark plugs, also cleaned throttle body and injectors. Its exactly same as described in original post above. No rpm issue or vibration when Ac is ON or headlights are ON..

 

[Double G]

How about cleaning the mass air flow sensor? Use cleaner specified for it, use as directed and be gentle. Air filter clean? Check for vacuum leaks?

 

[Naj]

No visible vacuum leaks. Cleaned MAF sensor. New air filter. But no change . Car is 125000 miles and drives smooth. Except for this low rpm issue in drive and reverse.