LS400FAN

I'll keep this story short and simple, any suggestions will be greatly APPRECIATED. Thanks to Yamae and Cowboy, I began looking at replacing my ECU because I have a '95 LS with the recalled 50220 ecu, so I replaced it with a later model 50303 and everything improved almost immediately, the high idle and other problems went away. Even the acceleration picked up nicely, but there's just one little glitch, every now and then I will get a sporadic cel code 450, usually only at start up. I've never gotten this code with the old ecu so I'm starting to think this may be a recurring problem with the newer ecu (which may be the reason it was sold on Ebay). On the other hand it could be more advanced in that it detects a problem with evap sensor when the older ecu didn't. First question is do these sensors fail on a "normal" basis? Secondly, I thought it could be something simple like the fuel tank cap, but after I replaced it the cel did not reappear and I thought the problem was solved, but 4 days later it reappeared, should I replace the sensor or could this be a resident problem with the newer ecu? Thanks in advance my friends.

Yamae

I think you'd better to check the EVAP Pressure Sensor.
The link below may help you some although it's not about a 95 LS400.

LS400FAN

THANKS a bunch Yamae, when time permits I will check it out and report back with the results, thanks again we Lex-heads are very lucky to have you on board, you're always a great help, cheers.

LS400FAN

Yamae could you tell me where exactly is the EVAP Pressure sensor located on the '95 LS? The manual has a diagram but it doesn't tell you where is located on the vehicle, thanks in advance.

Yamae

Attached is for a 98. Sorry that I only have a drawing for a 98. It's located at the LH FRONT FENDER.

LS400FAN

Thanks again Yamae, I will report back what I find, cheers.

LS400FAN

Yamae I noticed the hose at the bottom of the carbon canister that goes to the tank in the air guide was pinched could that cause 450 code in your view?

Yamae

I haven't experienced that particular pinch and I'm not sure it is related to the code. But it should not be pinched. I worry that somebody might have dare pinched it. If so, there might be some problem hidden there.

OmariMack

You cannot use model 50303, it will throw error code because you don't have vapor pressure sensor on 1995 model

For 1995's:

Your original Ecm is either:

89661-50220 or 89661-50221 if Federal (49 state). Lexus new replacement on the TSB says to replace with 89661-50224

If California then your original Ecm is either 89661-50230 or 89661-50231. The TSB calls for 89661-50234

But searching a local Lexus parts site shows that number has been replaced with 89661-50235-85.

A 1996 Ecm will not work in a 95. It turns the check engine light on.

RelentLex

Hey omari and ls400fan,

I actually have just gotten the same exact issue. I installed a rebuilt 50303 ecu replacing my 95 50220 ecu.
immediately got a P0450 code.
I'm reading contradicting information. Some say 95 and 96 ls400 are identical cars and have used 50303 ecu in 95 cars with no issue.

But you're saying the 95 hasn't got an evap sensor.

can anyone else confirm this or shed some light?

does the 95 in fact not have an evap sensor?

RelentLex

I've also just found a 50225 ecu. Anyone know the difference between 50224 and 50225??

OmariMack

Hi RelentLex

Some model of 1995 Ls does not have vapor pressure sensor but it depend on what vin number # on your car .. I've seen people who have a problem with 303 because 50303 request who have an vapor pressure sensor it will match on ecu because of Harness wiring have vapor pressure sensor

I have 1995 Lexus ls400 and doesn't have an vapor pressure sensor i had wrong use 50303, it will throw at you an error code of P0450 ... Actually you cannot jump over number 50303 it will throw an error code :P0450

Give me your VIN number, I will check online from Lexus website

OmariMack

Yes you can use 50224 or 50225, I just order other ecu 50224 today and i don't want to use 50225 because it could be throw an error code again, as in case..

RelentLex

I see! Any idea which 95 models had evap sensor and which didnt?

My vin# is JT8UF22E0S0011067

thanks!

OmariMack

I just found research on Lexus website parts ,There are no vapor pressure sensor on 1990 to 1995 Lexus LS 400 only.

1996 to 2000 Lexus ls 400 does have an vapor pressure sensor


1996 ecm # is 89661-50303 = 1996 Ecm WILL NOT work in a 95 lexus ls400. It will turns the check engine light on and throw error code from: P0450

You need to return to ecm back who you brought it from

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For 1995 Lexus ls400 :

Your original Ecm is either:

89661-50220 or 89661-50221 if Federal (49 state). Lexus new replacement on the TSB says to replace with 89661-50224

If California then your original Ecm is either 89661-50230 or 89661-50231. The TSB calls for 89661-50234

But searching a local Lexus parts site shows that number has been replaced with 89661-50235-85. (California)


QUOTE=RelentLex;10394594]I've also just found a 50225 ecu. Anyone know the difference between 50224 and 50225??[/QUOTE]