golfindude

Hello All,
I've lurked on this forum every time I have a problem with my GX, but have never joined or posted until now. Our 2004 GX has been a great car, but is suddenly doing a number of strange things - like not start. When I say it won't start, I mean you can turn the key, the dash lights up, the steering wheel adjusts, radio goes on, etc, but then NOTHING! No solenoid "click", no starter noise, NOTHING! Does not crank at all. The car just turned 60,000 miles, is in great shape, lives in the garage and has never been in an accident.

After the first couple of times it did this, had the battery replaced, as it was getting close. and then the car started again. Until the next day. No rhyme or reason as to when it would do this. It might start 10 times in a row, then NOT start for a while, then magically fire up instantly, even after several key turns. I wiggled the key, tried a different key, shifted to Neutral, wiggled the shifter to try to rule out security interlock, bad ignition switch and shift interlock. No dice.

Did some more research and thought it might be the starter relay - banged on it and it started, so replaced that part. Didn't solve the problem. It also began to randomly die while idling (in park, or in drive). Sometimes it would re-start, sometimes not. The times it has done this, it typically dies after running or 15-20 minutes, but NOT ALWAYS.... Sometimes it will die once, then be good for the rest of the day. Sometimes it re-starts immediately, after a few minutes, or more recently only after sitting for a few hours..

So basically we can't use the car. Took it to a local Lexus shop (not dealer) and they charged $60 to do a diagnostic, but couldn't figure it out. They asked if the car had been wrecked or had parts replaced to give them a starting point for further exploration; told them never. Now they want to charge $120 an hour to keep trouble shooting, so I told them no. Figured I'd pull the battery cable to reset the ECU and see if it would drive a bit to re-learn codes before taking it to the dealer if I can't figure it out.

So, has anyone here had this problem, or have any thoughts? I'd prefer to spend my own time on this instead of paying a fortune for their time. Any ideas are GREATLY appreciated! Sorry for the length of this post, but wanted to be as complete as possible. Thanks in advance!

470reasons

You've done a very good job of trouble shooting!

I'd try reaching under the dash with the engine running. Pull on the wiring and connectors to see if you can make it stall. Try the same thing in the engine compartment. Could be the ignition computer module is going bad - probably best to go to the dealer for that diagnosis. Check the vehicle history for flood damage. Flood damage can cause all kinds of weird symptoms years later. Definitely let us know the final outcome!

golfindude

Hi 470! We've owned the car since it was new, so no water or other "hidden" issues. When it starts again, will try pulling on some cables, etc. Unfortunately, further research is starting to lead me to think its the ECU; maybe even bad capacitors, as there is another long thread on CL about similar problems with earlier Lexus and Toyota vehicles. At present the "not starting" problem is getting worse, is taking longer between starts, and almost seems to be related to heat, as once it sits over night it starts right up.

Hoping it's not the ECU, as that's BIG BUCKS. Anyone with thoughts on other relays, etc. to check that might fail once the car get up to temp? Thanks for your thoughts!

Gene01

Check the battery terminal connectors (where they attach to the large cables (especially the positive one). They sometimes have hidden corrosion at the joint.

golfindude

Hi Gene,
Cables looked good when I swapped in the new battery, but does make sense to check them again - would be great if it were that simple! Unfortunately, that wouldn't explain the car dying at idle periodically. Thanks for your thoughts!

chiph9

Do you have an aftermarket alarm system on it? Or did the dealer have one on there that they disabled when you bought it? They're notorious for being flaky.

Chip H.

golfindude

Nope, no after market parts or mods; the car is completely stock.

mann777

Have the MAF cleansed and throttle body also. And let us know

golfindude

Hi Mann,
Is this to address the engine dying issue? The engine runs fine - until it doesn't. Seems more of an idle signal issue caused by ECU, but still trying to figure this mess out. Thanks for your thoughts!

Yamae

I would simply check the neutral safety switch attached to the AT unit before bark.

mann777

Yes dying issues can be many from Battery dying, ECM dying , Start Generator slowly dying or Fuel Filter being clogged, Fuel delivery flow lines clogged, Fuel Injectors clogged, the Port fuel Flow injection may experience clogging, Low fuel pressure from the tank, low Fuel Pump resistance. You will never get Warning or any codes on the ECM. I have been thru this. I had to start from the MAF and then slowly go all the way and found that the Fuel pressure was fine but not delivering enough volume to compensate and the fuel lines were clogged with some white sediments. I had to clean the entire Fuel Tank assy, the fuel breather pipes The fuel suction pump, the connectors , I had to replace the retainers as they broke along while disconnection. There was a bit of debris within the tank. Completed the fuel tank job and the others connected to fuel delivery to the engine. And the truck began to run smooth since then.
I had exhausted all options and then finally this nailed the issue. Maybe not you will have the same issue like mine, but you have quoted was similar to the defects I had.

golfindude

Thanks Yamae and Mann,
Will be sure to check the neutral safety switch, as I'm pretty suspicious of that. If I can get it to start reliably again, I'll tackle the random stalling thing, although I think that might be caused by ECU, as we also just replaced the battery and it's possible it hasn't gotten the idle learned yet. Will let you know what I find as I continue searching for the problem(s)!

wallen

Golfindude,

What part of Texas are you in?

The problem with your truck is sounding a lot like a failing ignition switch to me.


-W

chiph9

Ignition switch is a good idea to follow.

Do you have a lot of stuff hanging off your key? That extra weight causes wear on the switch.

Chip H.

vxphan

it's 2004 model, so no warranty now. But Lexus dealers still can troubleshoot with no charge