Adaptive Cruise Control Issue

e36er · September 18, 2020

For the first week or so of ownership the adaptive cruise control wouldn’t allow me to set the following distance. I assumed I was doing something wrong, but it suddenly started working. Unfortunately, it’s now reverted back to its non working ways.

Anyone else had this issue?

Herbie · September 18, 2020

If you've not had the car long get it back to the dealer you bought it from and get them to put it right under warranty because it could turn out to be a very expensive problem.

Texas · September 18, 2020

Forward facing microwave transmitter is not physically impaired in any way you can see is it?

Note: The Cruise Control system can also be used in ‘standard’ mode and you have not inadvertently entered this mode have you?

e36er · September 18, 2020

10 hours ago, Herbie said:

If you've not had the car long get it back to the dealer you bought it from and get them to put it right under warranty because it could turn out to be a very expensive problem.

I bought the car privately so that’s not really an option.

3 hours ago, Texas said:

Forward facing microwave transmitter is not physically impaired in any way you can see is it?

Note: The Cruise Control system can also be used in ‘standard’ mode and you have not inadvertently entered this mode have you?

Ooh, where’s this microwave transmitter doofry located?

Normal cruise control mode works as normal, so not that.

scott-o · September 19, 2020

Looks to be behind the Lexus badge, realised when I took mine off during radiator swap.

Didn't realise you could use the cruise like a traditional cruise control rather than adaptive either!

LexIS200Sport · September 19, 2020

Just to be clear, is it just the distance control that you have issues changing? The adaptive cruise works okay otherwise with the default distance setting?

If yes, maybe the distance control switch on the steering is faulty. The car is ever so ready to throw a fault if the radar unit has gone wonky, which I'm guessing isn't the case?

LexIS200Sport · September 19, 2020

7 hours ago, scott-o said:

Didn't realise you could use the cruise like a traditional cruise control rather than adaptive either!

Yeah, simply push the cruise control stalk forward (away from you) toggle from adaptive cruise to normal cruise. It's in the owners manual 😛

Texas · September 19, 2020

Normal Lexus embalm for a IS shown below and then an IS fitted with ACC.

scott-o · September 19, 2020

1 hour ago, LexIS200Sport said:

Yeah, simply push the cruise control stalk forward (away from you) toggle from adaptive cruise to normal cruise. It's in the owners manual 😛

I had a look after my last post and tried it out earlier and would you believe it worked haha also didn't realise you could up the speed by smaller increments than 5mph, didn't try that though, just read about it. Will try it next time I get on the right stretch of road!

Texas · September 19, 2020

In ACC mode the increments are 5 mph and in normal mode it is 1 mph.

C.B · September 22, 2020

Every days a school day, no idea you could use it as normal cruise. I do find it a bit rash on the braking and accelerating front, it doesnt hang about getting up to speed in particular!!

Twellsie · September 23, 2020

i had no idea you could change the distance!!!

ubersonic · October 12, 2020

On 9/19/2020 at 7:58 AM, scott-o said:

Didn't realise you could use the cruise like a traditional cruise control rather than adaptive either!

It's a feature they include on all cars with radar cruise in case it refuses to engage due to heavy rain (or malfunction, but it's mostly so people can still use cruise in a rainstorm).

scott-o · October 12, 2020

8 hours ago, ubersonic said:

It's a feature they include on all cars with radar cruise in case it refuses to engage due to heavy rain (or malfunction, but it's mostly so people can still use cruise in a rainstorm).

My golf r didnt have a normal function, it was the first car i experienced with adaptive cruise and i really didnt like it at first. Fully expected it to have a normal function for the reasons you stated but when i asked the question it didnt. Thats partly why i was (pleasantly) surprised the Lexus had both options haha

Texas · October 12, 2020

14 hours ago, ubersonic said:

It's a feature they include on all cars with radar cruise in case it refuses to engage due to heavy rain (or malfunction, but it's mostly so people can still use cruise in a rainstorm).

The Lexus ACC will work in heavy rain but as soon as your wipers go into high speed ( either via the rain sensor or you switch to high speed via the stalk) the ACC wil drop out!
The wipers might go into high speed for a split second via the rain sensor and the ACC will drop out even though you didn’t see the wipers go fast!

e36er · October 13, 2020

On 9/19/2020 at 3:43 PM, LexIS200Sport said:

Just to be clear, is it just the distance control that you have issues changing? The adaptive cruise works okay otherwise with the default distance setting?

If yes, maybe the distance control switch on the steering is faulty. The car is ever so ready to throw a fault if the radar unit has gone wonky, which I'm guessing isn't the case?

Yep, just the distance control. I've given the button a damn good pressing, but to no avail. I'll see I can get the button off and squirt some contact cleaner in there.

On 9/19/2020 at 7:58 AM, scott-o said:

Looks to be behind the Lexus badge, realised when I took mine off during radiator swap.

Didn't realise you could use the cruise like a traditional cruise control rather than adaptive either!

Thanks for that, I'll have a look to see if the connection is loose.