Why not? The reason I am asking is that after looking at the diagram the pump looks very similiar to the fuel pump I replaced in my Camry... which took maybe an hour.

 

This worked out so much better than I ever imagined it would.

The dealer found that the pump had come unplugged. They plugged it back in, vacuumed and washed the car, and charged me nothing. I even had a loaner RX for the weekend. Larry H Miller Lexus FTW.

I wanted them to show me the part that was unplugged but it was the end of the day and I didn't feel like I could take the mechanic's time after they fixed it for free. This was his report:

"PERFORMED DTC INSPECTION, FOUND DTCS P1235, P0200
PERFORMED VOLTAGE & OHM TESTS
FOUND LOOSE CONNECTION AT DIRECT FUEL INJECTION DRIVER
SECURED CONNECTION, CLEARED DTCS & ROAD TESTED."

I suspect the direct fuel injection driver is the high pressure fuel pump several of you have mentioned. Does anyone have a photo of where this is located? Sure would have been nice to plug this back in myself while I was on the side of the freeway.

Anyway, the dealer was honest and treated me right. They mentioned the recall work they had done recently, but didn't say if this was related. After the free repair and loaner car, I didn't want to ask. The car runs like nothing ever happened. If you get the P1235 / P0200 codes, it may be the connector.

 

Plug possibly got disconnected during one of your recalls/TSIBs perhaps? That wouldn't be something "normal" that someone would be missing with. Glad you're back on the road now and NOTHING out of pocket!

 

Bringing this back to life, this just happened to me tonight. Died at a stop light. Pushed it to the side of the road. Waited a few minutes and it started with the check engine and vcs lights on. Ran for about 1/2 mile and died. Waited again and started again. Luckily I was only about a mile from home. Is this connector at the fuel pump or engine side?

 

Well OP had his unplugged post recent recall. Did you just have your recalls completed?

I have not checked yet, but this could be as simple as a fuel pump relay if there is one on this car.

 

It actually appears that the ECU on the front/passenger side of the engine was not properly tightened. I talked to my local Lexus service adviser and he suggested to check that as it's fairly common after having work done. Some weird things apparently happen when it's not grounded properly.

 

Can you send me a picture of the connector you are talking about I would really appreciate it thanks in advance

 

I just got this code come up, p1235 and c1201. Does anyone know where is the connector is that the OP mentioned that the dealer plugged back in? Is it under the back seats?

 

It looks like the injector driver. Behind the snorkle from airbox.

 

2006 IS350
I been dealing with this code for like 2 months and I can’t seem to figure out how to fix the problem. Over a year ago this code popped up 2 times but I would just clear it with my OBDII scanner and it never came back up until recently.
2 months ago whenever this code comes up my car will be in limp mode. I go to clear the code the car drives normal and the CEL will stay off until the next day and the CEL comes back on and the car is back in limp mode. Now whenever I go to clear this code as soon as I start up the engine the CEL immediately comes back on and the car is in limp mode.
When this code started to come on 2 months ago, I first checked the fuel injection driver to see if there’s any loose connection. I didn’t see any loosen connections but I still disconnected all the connections and reconnected everything hoping that'll be the solution. The CEL went away for 1 month I thought that solved the problem but the code came back.
After the code came back I bought a used HIgh Pressure Fuel Pump from ebay and had it installed. The code went away for 2 days but then came back once again.
The last thing I could think of is replacing the fuel injection driver ecu. So i bought an used one from ebay and installed it. Thinking that I finally solved it but after 4 days the CEL came back.

Now I am stumped. I have replaced both the HPFP and the direct fuel injection driver but still no solution. Both were used but I doubt that they also have the issue that I am experiencing. I have no other idea what can be the issue and what can be the solution.

 

I found this trouble shoot for a IS250. I'm not sure if it's the same for the 350. Since reading this thread I would look at all grounding points on the injector driver. I think it's behind one of the studs. Make sure all connections are secure. Start at HPFP and work your way to ECU.

Make sure car battery is disconnected at the negative side. Don't take the risk of frying a component.

How are the engine grounds? One on each valve cover. One on the steering rack under the lower air filter box, and of course ground to body for battery.

 

That fuel pump issue was a widespread problem with both Toyota and Lexus. So many car even 2019 on back suffer this problem. Do consider that you bought a part used that could possibly have the same problem as if your car was parted out. I also remember seeing some info over the years where carbon cleaning cleared this code oddly? But I would look to a new part vs used replacement 1st if it was me.

 

I already looked at the ground that's next to the injector driver and it looked good. I still disconnected it and reconnected it in hopes it does something but didn’t fix anything. im going to take a look at other grounds throughout the engine bay when I get the chance later today.

A new HPFP cost over $1k new from the dealer so I am not trying to purchase a new one. I am considering buying another used injector driver ecu in the slight chance that the one I got already had the same problem.

 

Jeeeez I didn't know it cost that much. How much was the used one?

 

I got it for $110 +shipping on eBay. Even my mechanic was shocked that it costed that much for a new one even he had to look it up because he didn’t believe me.
My mechanic thought with changing the HPFP my problem would be fixed so unless the one I got was defective already good thing I didn’t buy a new one because I’ll be very sad if I had paid $1k and to not fix the problem.