Really liking the RX500h.

But, it threw a Check Engine Light.

The on-board diagnostics say vacuum leak. The shop has found not leaks and on-board electronics show no electronic faults.

The CEL and vacuum leak code re-appear after clearing.

Next step is for the Lexus regional team to assist with hook up with their PCs/diagnostic tools and get deeper into the diagnosis and trouble shooting.

In the meantime we have an ES300h as a loaner.

Will share what is found/fixed.

 

This is a strange problem to have on an engine with direct injection - usually it would be the pump being bad or a visible leak/loose hose assembly.

 

That is what the shop thought. Find the loose hose, restore the connection, clear the fault and good to go.

 

Yikes hope they find the fix!

 

Damn, that blows! Hope they find the issue.

 

After extended trouble shooting including technical assistance from Lexus no mechanical or electrical faults were found. They went ahead and reset the codes, did multiple drives with stop/start cycles and the fault stayed cleared. So, attributed to a ‘glitch’ yesterday and we took back the RX.

Driving fine, no CEL. Hopefully it was only a ‘glitch’. Will post back in the future if it stays clear or reappears.

 

Well, 3 weeks later it threw the CEL and put the check engine message on the multi-function display, again. Back into the shop.

To say I’m disappointed is a understatement.

Will share what, if anything, they come back with this time.

 

@Tacoshawn but the car seems to drive fine?!

 

They aren't looking hard enough for the mis-fitting hose -- loose clamp, etc. You are sure they are communicating the correct code to you as a "vacuum" leak, and not a leak in the evaporative emissions system, which spans the fuel system sensors, etc? Did you refuel the car shortly before (1-2 days) the light came back on?

 

Friday update, the car was driving fine.

The service department called today and want to keep it to get Lexus out to help with deeper dive into the RX. We are heading out of town next week and told them they can have it as long as they need.

 

Gas cap. I can tell you how many times that has thrown a CEL.

 

Indeed, that's why they have to be precise about whether the code is vacuum, or evap emissions. You can't diagnose a bad gas cap without simply replacing it as a precaution and seeing if the CEL comes back (or extinguishes on its own). The dealer must know this I assume, so it really must be a vacuum issue.

 

Another update to be followed by a pause. Root cause remains unknown, Lexus is involved and has shared with dealership that there is an issue related to CEL warnings on some RX500h.

The 500h will be staying at the shop until root cause is resolved.

My speculation is it is a software/limits issue and they are having to turn a S/W build and validate before turning it back to us.

We are out of town and will pick up a service loaner when we return next week.

 

Maybe this is hold up for all the news one not being delivered or being moved to transit.

 

@Tacoshawn appreciate the update! Stay safe when out of town! At least its not mechanical?!