Lexus RCF cruise control on rainy day?

[DamianLEX]

Hi,

I have been wondering if you have same issue. 

When it is raining I cannot keep cruise control on. 

I switch it on but it turns off immediately.

I called Lexus and they said it is a safety feature.

In my Volvo S60 there is no problem whatever the weather is.

In a GT car like RCF few drops of water and it is done.

Isn't it too sensitive? It is so annoying not to have such a basic feature.

[Linas.P]

Is there particular combination of settings or something, like maybe you driving in sport+ with stability control off? I haven't driven long enough RC-F to ever notice it, but that never happened to me on RC200t. Now sure RC-F is quite different beast, but I tend to believe something as simple as cruise control (and I assume you have standard cruise control in mind not DCC) would be exact same system in both cars.

I would assume that if car senses that it looses grip, it may disengage cruise control, but not just because it started raining. As well I don't buy Lexus answer that this is safety feature - maybe they just don't want to get involved in diagnosing what could be very intermittent and difficult problem to find and potentially very expensive to repair. 

These are condition under which cruise control would get cancelled (p277), rain is not one of them:

Quote

■ Automatic cruise control cancelation Cruise control is automatically canceled in any of the following situations.

● Actual vehicle speed falls more than approximately 16 km/h (10 mph) below the set speed.

● Actual vehicle speed is below approximately 40 km/h (25 mph).

● VSC is activated.

● TRC is activated for a period of time.

● When the VSC or TRC system is turned off by pressing the VSC OFF switch.

 

[Legendliving]

Took a while to work this out on my RCF. The adaptive cruise cuts out when the windscreen wipers are on the fastest speed. Slow down the wipers and the cruise control comes back on. 

[steve2006]

Nice bit of information there John.

[DamianLEX]

Wow that’s a handy tip. Thank you 

[Yuss]

I had the same issue during heavy rain with ACC but I usually switch over to normal cruise control mode, good to know slowing the wiper can resolve this.

[HughTwo]

Same issue with the ACC, will have to try the wiper settings, normally have it on auto and the ACC will switch off in rain.

Can't recall having a similar issue with my 2017 Golf, and although reluctant to say it, I think the ACC on that was superior to my RCF.

[Legendliving]

I agree, other cars have a more sophisticated arrangement where the quantity of rain or snow on the sensors or reduced visibility due to heavy fog turned off the ACC, but in the RCF it is a simple switch relationship between the wiper speed and the ACC. My 2007 Honda Legend had a much better system. Next time it rains I’ll test it on my GS.

[ColinBarber]

On 1/28/2022 at 10:02 AM, Yuss said:

I had the same issue during heavy rain with ACC but I usually switch over to normal cruise control mode, good to know slowing the wiper can resolve this.

Both high speed wipers or 'poor' weather will cancel adaptive cruise and it will just state cruise control is not available - as you say, you can just switch to normal CC.

If either of the conditions listed below occurs, the driving support ECU assembly cancels speed control by the cruise control system while retaining the set vehicle speed in its memory.

• The wipers are operating at HI speed.

• The measurement becomes extremely unstable due to poor weather conditions.

Cruise control is prohibited until the normal operating conditions are met or the cruise control system is turned off and back on again using the ON-OFF button on the cruise control switch