2012 Lexus GX460…great car…but dash lights keep coming on and going off…no obvious reason? 4LO and Check Engine lights come on for 1-2 days with no other symptoms, then go out. One thing we notice is that the gear shifter seems to be harder to shift, and the gear indicator on dash panel does not display…Weird…then lights go out and everything else is fine.
Every now and then the car will lock up in 4LO…it can’t be driven. Then lights go out and all is fine.
Sometimes we loosen gas cap or add gas, and that fixes.
This seems to be somewhat common among toyotas(??)…any remedies out there?
Option 1) Live with it. Cost Free
Option 2) Take it to an independent mechanic, maybe a transmission specialty shop (no chains!) for a second opinion and estimate. Cost…Who knows? But likely less the the dealer.
I have a 4WD Ford truck, but no experience with Lexus 4WD. So what you are hearing is the best way to replace failing transfer-case actuator is to replace entire transfer case? hmmm … could be I guess, maybe there’s less labor. Or maybe dealer is aware that when that actuator fails, often other xfer case problems lurking. I think what I’d do if I had that problem myself is ask the shop if it might be worth a try just draining and replacing the xfer case fluid. Or ask the shop if it is possible to configure the car so it only uses 2WD mode.
There have been some recent posts here at Car Talk forums about 4WD hub actuator problems. But don’t recall many about xfer case actuators. OP, you could search through the forum history here, posts about this problem. Search link is upper right this page.
Thank you for your comments…and yes the dash lights problem is very sporadic…it might be off for weeks…then come on for several hours…then go out again.
Car drives fine when lights are out…but very hard to shift the gear stick when they are on
Did you ever figure this out? My 2013 GX has no gauge lights but 4lo flashes and CEL on solid, vehicle is also in limp mode. Pulled codes and got p1340 p0617 and p0335. I’m highly suspicious of water intrusion from an overly aggressive new car wash near my house (blow dryer forced air past the sunroof seal and down the a pillars). Went through this several times over a few weeks before I figured it out, sporadic issues sounded like what you experienced. Pulled ECU and sent to SAI computers and they couldn’t find issue with ECU. I bought a used body control module and I still have exact same issue. I’m now leaning toward checking the camshaft sensor on passenger side and the crankshaft position sensor. Any advice anyone?
p1340 indicates a problem with the camshaft position sensor’s function
p0617 indicates a problem with the start-engine function
p0335 indicates a problem with the crank position sensor function
I’d be inclined to focus on number 1 and number 3, and just monitor the situation for number 2 until 1 and 3 are corrected. For 1 & 3, try to figure out a way to display the crank and cam position sensor waveforms side by side, and compare them to what they should be. The engine will never run correctly when those waveforms are incorrect or not properly sync’d to each other. The problem is more likely internal to the the sensors, or their position w/respect to the tone rings, or dirt contaminating the sensors or the tone rings, timing chain/belt problems, or faulty variable valve timing mechanisms/sensors, or the electrical power supply to the car’s computer system.
