Help diagnosing check engine light/ Limp mode

[wakejunky]

I see how it is.

I've been doing some research and gathering up some test data directly out of the manual. I don't have a scanner or it would be posted all ready. Any who, the only time the engine goes into limp in mode is if there is a problem with the ETCS (electronic throttle control system) The ONLY problem we see at the dealership is with the throttle lever sensor. However it can also be the throttle motor itself, the TPS, or one we do see occasionally at the dealer is " improperly installed parts".

So before you start barking up a tree.
 remember i can not physically see or test this problem with my own eyes. I am not the one installing parts. I don't know what level of mechanical ability you may have. YOU are the one THROWING parts at a problem. your to cheap to get the proper tools to do the job right. I am giving you my real world experience and suggestions but the does not guarantee that whatever i suggest will fix your problems. I'm not saying its your bad. I'm giving you free advice. giving you the typical problems I see at the dealership. Just for your reference I've been working for Toyota/Lexus for over 10 years. I am a master diagnostic specialist. Not some freakin noob.... So if you want some one to help you out I will. BUT don't be an ASS.

 I'm across the freakin country for god sake. I'm not sitting in your garage with the proper tools, testing the involved parts, and coming up with a proper diagnosis. I rely on you to meet me half way and test things the way i ask. If you don't know what I'm asking you need to state that. Don't just assume and say its bad or good just because you don't know how to test something properly. If you are tearing into every possible thing because your too impatient you may be causing more problems and not even realize it. If you want help you need to meet me half way and not let you EGO get to you. Its real easy to sit behind a computer and bitch

If you don't want my help then PEACE OUT and good luck.

So "Epic Mariners" you decide..........You want help let me know.

[kirk_tx]

Again.... Where did that come from.

No one is talking trash.  Especially not me.  I just want to get out on the lake.

You told me how to test the 'ETCS'.  I did as you asked. and it failed.  You recommended the Throttle Lever sensor, I replaced it.   Thats basically, it.... I did all that you asked.  If I missed something, I apologize.

All this started when I asked about the computer and diagnostic scan tools, I was then told that we should be able to diagnose without the computer.  Soooo, hence the throwing of parts at a problem.   Also, I would be happy to purchase the 'right tools' if someone could point me at them.

Trust me, I know flyin and he didn't mean anything by his comment.  And I don't think anyone is bitching.

All that being said, back to the issue...

I think we have come full circle and I need Diagnostic computer.  Unless someone can tell me how to test the throttle drive motor?

In the manual, does it say what the OBDII protocol is?

[flyn2001]

I've been working for Toyota/Lexus for over 10 years. I am a master diagnostic specialist. Not some freakin noob....

Your to cheap to get the proper tools to do the job right.

... don't be an ASS.

Its real easy to sit behind a computer and bitch

Let me get this straight...since you have worked at Lexus for a number of years, you can come on the website and call someone you don't know CHEAP and an ASS?   Not cool dude!...Kirk is neither and has not portrayed these characteristics at all during the discussion!  He is simply trying to solve an issue with his boat so he can use it.  For future reference, just so i'm clear...when someone doesn't follow your advice you are going to question them, but when they do (and it doesn't work) they are a cheap ass? Noted! 

[wakejunky]

Just to clarify for you flyn2001.

Just because I work some where doesn't give me the right. Kirk has portrayed being cheap. I'm cheap too. He doesn't want to rent a $5000 scanner that will help with his problem. He is buying cheap parts at autozone for a tundra not a Lexus engine and then modifying them. However I wouldn't rent the scanner either and I do try to diagnosis by symptoms because even if you have the scanner your going to get a code like this " P1540- Electronic Throttle Control System Failure" which we already know. It most likely will not give a specific part failure. Just my experience. AND no he is not the ASS! will leave that honor for me and you.

Kirk_tx- i apologize for being an ass. The manual says nothing about OBD II protocol. You now have noticed it hunting for idle. Is this new or has it always been a symptom? Every bit of info helps. Did you remove the TPS for the dealership to test? or was it just the MAF and the throttle lever sensor? When you turn the key to the on position do you get a buzzing noise from the throttle body area? You should.
I will try to get the pages from the manual posted as soon as I can. They will show how to test the throttle drive motor, the TPS and the throttle lever sensor. It will also show how to properly install those parts. You will need a DVOM (digital volt and ohm meter) an analog one will not be accurate enough. they are however only basic ohm reading tests, they may not show a problem that does exist. It will only show if there is an internal open circuit in each part. even though you have replaced the throttle lever sensor I would test it anyways. the factory lexus part has dual circuits inside to make the sensor more dependable. I dont know if the tundra sensor or an aftermarket sensor has the same dual circuits. The tundra has a much higher failure rate then the LS400.
have you noticed any other symptoms?

[flyn2001]

Well said Wakejunky, sorry for being harsh as well.  How about we all leave the sarcasm behind and try to help each other enjoy years of fun within our small, but tight knit, community.  Good luck Kirk, also, you know where I live so you can always ride on my boat!  Amistad is about 30' low right now though!

[kirk_tx]

Sorry for all the trouble this has caused.

No other symptoms to speak of unless I am just not noticing something.  It starts up fine, and runs.  But the light comes on and it is in limp mode.  It does hunt for idle for a about 45 seconds or so. 
Yes, I get a buzzing sound as soon as I key it on.

I took all the sensors I could think of off at one point and called every Toyota dealer here in Dallas to see if they would test them.  None of them would test the individual sensor.  They would say "just put them on the car and we will hook it up to our computer.  No need to test them individually", once I told them the full story, they all tried to get me off the phone fast. 

I was buying autozone parts because I could return them if they didn't fix the problem.  I guess I will either get a manual myself or if you guys get the testing methods posted I will go through them. 

Thanks for all the help.

[wakejunky]

it sounds like the TPS is out of adjustment, hence the hunting for idle. it could also be the MAF sensor installed backwards or if its internally shorted. they will all cause it to hunt for idle. Did you replace the MAF sensor or just clean it? Its odd that you are getting a Buzzing noise from the throttle body. That usually indicates the ETCS is operating correctly. try the active test i suggested earlier again and let me know what you have. i tried to even take pics of the manual pages but they are to big to post on the site. Ill try to find someone with a scanner.

[kirk_tx]

I will check again for the buzzing just to confirm.

And I am positive that the MAF is installed correctly.
I checked it an rechecked it several times I was nervous that would put it in backwards.   

I replaced the MAF sensor first.   With the exact some part number from autozone.  It was an identical denso unit.  But when the light didn't go off, I took it back.  Figured mine was fine. 

[kirk_tx]

Thanks again for all the help. 

A tip on taking pics of the manual.  If you put the camera in black and white mode and turn the pic size down to about 3 MP it helps out allot.  Thats how I do it with my camera, I assume others can be made to do that same.. 

[lesman01]

If you email me the pics i can post them in the maintenance section. might have to email them separately if they are large. I will make them into .pdf.

[bmccalla]

Hi gang,

I've owned an 99 EPIC 21 two seasons now, but have very limited time on the water so far. The Lexus mechanic replaced the MDC and I have a new battery, but all the gages are still dead. He gave up working on the boat. The lower half of the dash still works without the key, so I don't think the wiring is right, so I would appreciate some advice on the new wiring...exact gauge and length, fuses to buy, etc. I am going to do it myself. I can't trust the certified Lexus mechanic who worked on the boat for the previous owner. I found the paint on the impeller housing screws had never been touched since new, so was misinformed about the routine maintenance which I don't think was ever done. I replaced the burnt exhaust hoses and disintegrated impeller after the first time in the water. From my last two times in the water, I am also experiencing OK performance for about 30 minutes, then the limp mode thing. I replaced the fuel filter and will replace the fuel pump screens tomorrow. I have access to a boat mechanic who never worked on an EPIC before. He wants to bypass the MDC. I will try the easier stuff myself per all the great advice in the maintenance section.

Any advice to get the boat reliable would be appreciated. Feel free to email me direct at bmccalla@bellsouth.net. I am in Cary, NC.

[sailtl]

Gauge problem is probably a dirty fuse holder/fuse. The fuse holder is located about 6" from the Perko on/off switch. Turn off the power and get the fuse holder apart and clean it up good or replace the holder assembly if the corrosion is extensive. This should solve the gauge problem. There is a trouble shooting guide for the MDC in the maintenance section of the site.
I might also suggest changing the spark plugs and see if that helps with the run-ability.

[bmccalla]

Gauge problem is probably a dirty fuse holder/fuse. The fuse holder is located about 6" from the Perko on/off switch. Turn off the power and get the fuse holder apart and clean it up good or replace the holder assembly if the corrosion is extensive. This should solve the gauge problem. There is a trouble shooting guide for the MDC in the maintenance section of the site.
I might also suggest changing the spark plugs and see if that helps with the run-ability.

I think the previous owner modified the fuse location. The in-line fuse is attached to the floor next to the Perko master switch, so the carpeted engine cover narrowly misses it. It looks clean as new. I've checked the maintenance guides. Today both inlet screens (little nylon cones) for the fuel pumps were cleaned, but there was only a little speck of gunk in one of them which I got out with a paper clip. I do need some diagnostic help at this point. I think either the fuel pump gives out after 30 minutes or there is a TPS or other engine control module problem after the engine heats up. Again, I am with no dashboard gages to guide me (looks like thicker gauge wire has been installed from the Perko, I have a new battery, new MDC, new fuel filter, clean strainer) and do not have easy access to any Epic experts except this forum. No pinched lines and the fuel pumps prime with the fuel pump switch. If anyone knows the solution to the limp mode after 30 minutes in the water, pls let me know. Engine started fine again today with the fake a lake. The fourth boat mechanic I've talked to suggested checking for spark after the warmup failure so I can see if it electrical or the fuel pump(s). Would this be the next logical option? If so, would I check the spark plug for spark against a ground like I do with my motorcycle or can I use the fuel pump red switch to diagnose the problem?

On the plus side, the stereo and all 4 speakers work...

Thanks in advance

Bill

[bmccalla]

Hi again,

I have been following this thread and will probably replace the TLS as discussed. I would appreciate the manual pics once they are posted. MAF cleaning...is there a pic or instructions?

Thanks and sorry my posts sound so whiny. I want to get on the lake this summer.

Bill

[sailtl]

Does your check engine light come on when the engine goes into limp mode? It is the red light above tach. If it comes on you may want to rent the tool to check codes.