whitesnake SC400

P.S. error code 24 appears after driving some time on a freeway at speed over 50mph. When i drive inside city check engine light does not light up. Hope it adds some info in order to identify what's wrong with my car.

Thanks JZZ, is there reliable procedure to identify shot MAF or O2 sensors?

Hi, i have check engine light with "lean fuel mixture" error code (most common failures for this code are airflow sensor or oxygens sensor). I took car to Lexus dealer. They diagnosed fault in air flow sensor and offered to replaced it with a new unit (price approx 1400 usd!!!). I told them that they were full of *BLEEP* with this pricing. I am not completely sure dealership got diagnostics right. Engine runs and idles fine. Fuel consumption haven't increased noticably. When i unplug MAF i observe rough idling and car jerks when i drive at low rpms. Is there a way to confirm failure of AFM with ohmmeter tool? I checked resistance between each electrical connectors (pins) of AFM but only 1st and 2nd (if you count frim the right side of installed sensor) had some impendance while other pairs were open circuit. Hope someone had done it before and could advise. Best regards, Stan

It could be brake calipers. They do not fully release rotor, then after driving at high speed it heats up and starts vibrating. Check if one of your wheels becoming warmer than others.

Has anyone of you solved the issue? I have same symptoms. After erasing engine error codes it (code 25) reappers after driving of highway for several minutes.

From my experience, you don't feel the difference at all. It's costy procedure and labor intensive to replace belt. something like 5 hours of labour. Fuel pump and belt tensioners are replaced during procedure.(I also suggest replacing distributor caps and front crankshaft bearing if it leaks any oil) I replaced my belt at 150kt (i am not sure if it was original one) when water pump started leaking.

I have installed KYB (which are original parts) and i must admit those are not top reliable. Some of them failed after mere 20k miles.

Well, if it is code for brake fluid reservour, then 1st- add some brake flued 2nd - if it doesnt help, then try to play with wires that are connected to brake fluid level sensor. Try to disconnect it or short circuit them. And see if warning dissappears. If it doesn't help, then it's probably not the code for brake fluid reservour cap. Search this forum for list of error codes. I saw them here.

Graham, that's nice service manual! Mine SC400 is 190k now. Still i haven't done any tune ups like sparks, wires , distributor caps or fuel filter, although i own it since 130k. I am afraid to take engine appart since it runs fine!

Hi there. I've got 190k on my tranny. It runs ok. I owned a carg since 130k miles. Replaced tranny filter once. Color of transmision fluid is fine (brown-reddish). However tranny is slightly overfilled. I checked dipstic and see that level is above "hot" range even though i was checking while tranny was cold. Should i do anything about it at all? Car shifts and drives ok.

Hello, i've found several good manuals how to manually pull Lexus engine codes (without code reader tool). However i am not sure where code reader connectors is located in SC400. Some sources indicate it is located somewhere under steering wheel. Where exactly to look? The picture will certainly help. Best regards, Stan '93 SC400 180k ...exported from US to EU

May anyone please add a picture where diagnostics socket is located under the steering wheel on SC400 ? Or at least more detailed explanation where to find this socket. I do not have error code reader but i've read how to manually pull the codes via "engine check" indicator blinking pattern. Thanks

Issue is solved. I checked thermostat and it was stuck open. Replaced it. Coolant lines in engine bay are much warmer now. Climate control heats air much better now, i still wish it blew more hot air....next and last step i will do is to bleed air from cooling system.

You are right. Coolant level is always the first thing to check. Coolant tank is full and i did bleed the system (running full heating cycle with coolant cap opened). I've found good remark in another thread how to diagnose thermostat. To identify thermostat stuck open you should squezze radiator-engine coolant line while engine is running cold. Coolant is not supposed to circulate via radiator during when engine is cold. If you feel pressure builds up within coolant line while you are squeezing it , then it mean that thermostat is stuck open.