Map Sensor

[NILEX]

Hello all

My 2016 IS300h has thrown a CEL today, reading the fault codes it indicates an issue with the map sensor.

Did a forum search but did not come across any threads, has anyone cleaned/replaced the sensor? Where exactly is it?

Thanks

[200h]

Hi Alan

i have just had a look on jp-carparts and found this exploded view

https://jp-carparts.com/lexus/partlist.php?maker=lexus&type=242130&cartype=9&fig=8404

i think it is item 89421 SENSOR ASSY, VACUUM (FOR E.F.I.)

as this is the only pressure switch i can see.

[Andrew888]

Can try to clean it, sometimes works sometimes doesn't - However this part is seen on Prius's etc etc so its not that much of an "exclusive" expensive part.

 

 

[NILEX]

8 hours ago, 200h said:

Hi Alan

i have just had a look on jp-carparts and found this exploded view

https://jp-carparts.com/lexus/partlist.php?maker=lexus&type=242130&cartype=9&fig=8404

i think it is item 89421 SENSOR ASSY, VACUUM (FOR E.F.I.)

as this is the only pressure switch i can see.

Thanks @200h, that looks like it might be the part alright, will have a nosey to see if it can be cleaned but I suspect it is a dud as it's showing 0v to it.

@Andrew888, that would be the MAF rather than the MAP?

[Andrew888]

Generally the car would have one or the other and it would be MAF in our case of IS300H

 

[NILEX]

1 hour ago, Andrew888 said:

Generally the car would have one or the other and it would be MAF in our case of IS300H

 

Thanks @Andrew888, I did read that but was confused by the description on the fault code that suggested it was a MAP sensor.

I'll give the MAF a clean and see how I get on, cheers.

[matt8]

Is it recommended to clean these sensors proactively and regularly?

My understanding is that a dirty sensor can impact fuel economy.

[Andrew888]

5 hours ago, matt8 said:

Is it recommended to clean these sensors proactively and regularly?

My understanding is that a dirty sensor can impact fuel economy.

No harm in giving it a gentle clean. I normally use brake cleaner to give it a little blast. However, its a little filament and if you don't think its dirty then don't bother cleaning it. One thing to do clean though, is the cabin temp sensor which is hidden behind little slots by your steering wheel, try to get a vac on it to suck the dust out. Does wonders for your auto climate 🙂

 

[NILEX]

No luck with cleaning the MAF, will try replacing it.

 

See attached the fault codes

[Shada]

I would suggest having a competint mechanic do a proper diagnosis first. Some data from manifold and barometric pressure to assess then move forward. 

Throwing parts can be very expensive and on Toyota it's not usually the sensors that fail. 

[NILEX]

Thought I'd bring a bit of closure to this topic: -

After getting passed about between independent mechanics and the dealer where I bought the car, I ended up going to the main Lexus dealer in Belfast who diagnosed it as a faulty MAP sensor.

 

Yes, this car does indeed have both the MAP and MAF sensors, the one @200h identified is correct. Lexus wanted £230 for the replacement sensor. I got a used one on eBay for £25, installed in 2 minutes and cleared the codes using a simple obd scanner.

Job jobbed.