esdad71

Hello Forum,

A few months back I purchased a 1995 LS400 with about 170k on the clock. It was a 2 owner with full documentation from Lexus so I can see all of the records. It was well taken care of and I do not think anyone ever sat in the back seat. Water Pump and Timing done within last 50k. Engine is clean enough to eat off of.

Runs great. No issues. Well, for the first 4k. I then had an issue where it stalled. No CEL at this point. I restart, the RPM's are high(1200) on start and level out and I get the car home and run a diagnostic. I ran an OBDII and it tells me it is the Engine Coolant Temperature Circuit. Driving to the mechanic to get it replaced I get a CEL . P1600. So I take it in, get it repaired and no CEL's. Car is running good. 700 RPM. No issues.

Two weeks go by and at a light...it drops to 200 RPM and stalls. Starts right back up and for another week no issue. No CEL. No error codes in OBDII.

So, Lexus community, any ideas? I have looked around in the forums but most show multiple issues or the CEL 1600 not clearing.

Thanks!

dicer

I don't see any information on the code. Just what is stands for ECM Batt malfunction, maybe Yamae knows about it. Could be capacitor issue in ecu.

esdad71

I would have thought the same thing but I pulled the fuse and the CEL cleared. No issues. It just does it about every 6-7 times I use it.

Thanks!

RA40

iTrader: (6)

As supplemental reading:
https://www.clublexus.com/forums/ls-...capacitor.html

Yamae

Other than the common QAS capacitors issue, a 95 model has a known issue in the ECU.
See below and check the ID of the ECU.
https://www.clublexus.com/forums/ls-...xus-ls400.html

esdad71

I appreciate it. I just wanted to make sure that even if there was not a CEL now that it would not be anything other than the caps.

esdad71

Allright...I was tired of stalling every 3rd time i drove it and found a remanufactured ECU for 225 bucks. Had it sent and now I need to install it. I have read some articles online but none talk about potential gotchas with getting in there to replace. Is there anything I can break when removing the dash I should worry about. The car is in awesome condition for the mileage and don;t want to strong arm and break anything. I will be installing it this weekend.

thanks!

dicer

First disconnect the battery. And yes if not careful stuff can be broken. I don't know the details to get to it I don't know the gen 2's.

esdad71

Thanks Dicer. All I can find are Gen 1 Pre-95 videos....I an sure it will be ok but I wanted to know about anyu gotchas. You can watch all the videos you want but we all know we can get......stuck.

dicer

With the air bag and cd player around the glove box it makes all that real different. It isn't the easiest thing to do on the Gen 1's at all, the glove box is the main hassle.

RA40

iTrader: (6)

Most the screws to remove stuff are visible. There is one center screw behind the glove box that is kinda hidden.
https://www.clublexus.com/forums/ls-...glove-box.html

Be gentle when removing the wiring harness release clips.

esdad71

Ok. So it is in. I tested it. Perfect Idle. 650 RPM. Took it out and HOLY BAT ***** I have new car. I thought i was babying it before and knew it would not accelerate like my old MR2 but I not know what it is like to drive the infamous 1UZ-FE V-8 at full throttle. I am going to post the steps because there are a few things that are not mentioned that are there in the 95 that is not in any of the stickies for the 94 and older swaps. There is a cruise control unit that needs to be unplugged as well as two very hidden screws I did not see and caused a broken bracket.

Best 225 I have spent on a car....

Thanks for all of the follow ups and confirmations in my journey to get this resolved.

dicer

Yeah do a good write up with some pictures.

Banshee365

I wish I would have thought about you at the junk yard the other day. A 95 I was pulling parts off had a 2009 reconditioned ECM. I pulled it and left it in the seat. I could have sent it to you for $100 or so.