Very frustrated at the moment because I'm dealing with the owner of a big garage. He's a great guy, but he doesn't speak a word of English and my tiny vocabulary of Polish words doesn't include autoboxes. The wife is translating but... well, it's not easy.
The Lexus has 5 gears, all is normal until 2nd changes into 3rd. It just takes a split second longer and the engine revs an extra 500 rpms then it engages. Hardly noticable but it's not right. It's been like that for a couple of years. I asked another garage at the time to change the fluid and they said they had and nothing improved. Six months ago my current garage man sorted out a brake problem and as a lambda light had been on there for a few months he just cleared it with his laptop and I drove home. The gear change was like a different car - utterly perfect. It felt like all the changes were instantaneous. I took a long route home because it was such a pleasure to drive it. Next morning, the lambda light popped on of course and that lazy gear change 2 to 3 occurred again. So in my mind, it's a computer problem, maybe a sensor. It can't be a mechanical problem that suddenly coincides with a lambda light.
Anyway, this morning I took it to him again to sort out an unrelated niggle but I wanted to ask about the autobox, would it be a sensor or whatever. I drove it home with him so he could drive it back and I wouldn't need the bus. I showed him the 2-3 change, the rev up and then everything normal again. All this time wifey in the back is translating and of course I'm saying one thing and he's hearing another. Later back when he's driven off and I'm at home I finally get through to what he said - a slipping clutch - he'll check ATF and hope that sorts it. But I tried to show him exactly what happens and I don't think it is a clutch problem (or a 'band' as my old man says when I asked him why autoboxes have cluthes). It releases 2nd then moves to 3rd a split second slower than normal THEN engages and there is no slipping. No revving once it's in third. It's a lazy change. A dirty sensor. A computer glitch. Lambda-relative. These damned things are complex.
Anyway. I need to get the lambda fixed (oxygen sensor maybe) but can't get it done at the moment as I need to drive out of town on Friday but I think when it is fixed, the 2-3 gearbox change will rectify too. But when I pick it up later about something else I want him to clear the lambda so I can see if it works beautifully like it did that time.
99% don't care about the lazy shift, or even notice, but guys like us on a motoring forum will find it extremely noticable and when it doesn't deliver perfection, it ruins the pleasure.
Any engineers out there with any ideas? Over to you. Number Cruncher.
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>>I need to get the lambda fixed
I agree, fix the obvious thing that's wrong.
What was the fault code?
Perhaps the way to make your mechanic understand you is simply to ask him to fix the problem causing the lamp to come on, and not complicate the issue by mentioning the gear change.
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Hi NC. Yes, you're right, at the moment I'm probably just going to pay another unnecessary ATF change.
I never bothered with the lambda but I know it's part of the MOT test now and my MOT guy sternly wagged the finger at me - 'sort it before next time'.
I'll try and ask wife to ask mechanic the fault code. If it's a V-configuration and two pipes, I suppose there will be two sensors?
I know, I should have had the sensor sorted long ago, I'm lazier than the autobox.
Cheers NC.
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The problem is that the fault code doesn't necessarily tell you which sensor to change - it's just a hint about which area to look at.
Taking lambda sensors as an example, any fault which affects the air/fuel ratio can end up being registered as a lambda sensor fault - even if the real cause is something trivial like an air leak downstream of the mass air flow sensor.
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I forgot to say, the problem manifested at the gearbox, the "flaring" between shifts is something to get sorted out - even though the fault itself may be elsewhere - the slip in the bands / clutches which is going on won't be doing the gearbox any good.
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Thanks NC.
I'll see if they can find a solution quickly today, otherwise in a couple of weeks.
Just having two warped discs changed that has to be done now, they skimmed them six months ago (same guy). I asked him what the hell keeps happening to the discs, I drive to school and back not down mountains with a foot on the brake pedal. He said, there's no sewages or drains in this village but after a heavy rain, you're driving through deep water with hot discs. I think he's right. I should show you the piccies I took a few months ago. A village of swimming baths.
A should buy a dingy.
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Hi NC
PO 172
PO 175
PO 141
PO 161
P 1651
Cheers
D
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>> Thanks NC.
>>
>> I'll see if they can find a solution quickly today, otherwise in a couple of
>> weeks.
>>
>> Just having two warped discs changed that has to be done now, they skimmed them
>> six months ago (same guy). I asked him what the hell keeps happening to the
>> discs, I drive to school and back not down mountains with a foot on the
>> brake pedal. He said, there's no sewages or drains in this village but after a
>> heavy rain, you're driving through deep water with hot discs. I think he's right. I
>> should show you the piccies I took a few months ago. A village of swimming
>> baths.
I think "disk warp" is a very rare event these days, most disks are cast, two faces, ventilated vanes through the middle, a structure that is virtually warp free. Its more likely to be sticking callipers leading to bits of the disk not being swept and developing ridges. A skim will still fix it of course.
Last edited by: Zero on Mon 20 May 13 at 12:20
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That's a lot of fault codes. As I understand them, P codes are 4 digit, so the first batch are P zero number number number, not P letter O number number number.
I looked the first three up using my weekly "Gendan" allowance...
Fault code
P0172
Manufacturer
LEXUS
Bank 1 too rich
Probable causes
Intake blocked, Evaporative Emissions (EVAP) canister purge valve, fuel pressure, Exhaust Gas Recirculation (EGR) system, injector(s), Heated Oxygen Sensor (HO2S)
==============
Fault code
P0175
Manufacturer
LEXUS
Bank 2 too rich
Probable causes
Intake blocked, Evaporative Emissions (EVAP) canister purge valve, fuel pressure, Exhaust Gas Recirculation (EGR) system, injector(s), Heated Oxygen Sensor (HO2S)
==============
Fault code
P0141
Manufacturer
LEXUS
Bank 1 Sensor 2 Heated Oxygen Sensor Circuit.
Probable causes
Wiring, Heated Oxygen Sensor (HO2S), ECM
==============
I worry for your wallet.
If it was mine, I'd start by having a look at the air filter to see if it's clogged up (intake blocked as first fault option on the first two error codes according to Gendan).
There's also a minefield of stuff out there, much American, relating to problems with elderly Lexii, but you really need somebody who knows what they're doing.
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>>I'd start by having a look at the air filter to see if it's clogged up
Absolutely! Cheap, quick, and easy checks first!
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Pah, forum edit time limits suck!
In short, the 1651 code, being Toyota/Lexus specific means that it's beyond my meagre knowledge.
As there are a list of codes, it's likely that one fault is tripping all of the other codes. It might be worth clearing them, and seeing which one comes back first.
I also think that it's really important to find a garage who are going to diagnose intelligently, use the fault codes as mere hints, starting points for further thought and investigation, and not just throw parts at it - all the parts hinted at would cost a lot!
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Not worth the weeks wait, I'm afraid.
When something automotive is beyond Number_Cruncher's meagre knowledge, I should know better than expect a result from the database for a generic code reader: Code 1651 not known.
P1651
Sorry, we do not yet have the definition for P1651 for LEXUS .
==============
==============
Fault code
P0172
Manufacturer
LEXUS
Bank 2 Sensor 2 O2 Sensor Heater Circuit Malfunction
Probable causes
Wiring, Heated Oxygen Sensor (HO2S), ECM
==============
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>> Not worth the weeks wait, I'm afraid.
>>
>> When something automotive is beyond Number_Cruncher's meagre knowledge, I should know better than expect a
>> result from the database for a generic code reader: Code 1651 not known.
>>
>>
>>
>> P1651
>>
>>
>> Sorry, we do not yet have the definition for P1651 for LEXUS .
>>
>> ==============
>>
Using Google, first result.... www.lexusownersclub.co.uk/forum/topic/51687-p1651-code/
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Hi AJH
It seems that lambda problems are beyond the knowledge of my garage man too. I asked him to look at some kind of air leakage before fiddling with sensors. He said go to a specialist technician/electrician. I give up. But thanks John - I've been reading through the American Lexus forum - start by simply cleaning MAF sensor. The diagrams are really clear so even I can have a go when I have a spare hour.
Do you think by just disconnecting the battery for 20 mins, the dashboard lambda light will clear? Then I'll know whether it's the MAF or not.
Cheers
D
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>> Do you think by just disconnecting the battery for 20 mins, the dashboard lambda light will clear?
>> Then I'll know whether it's the MAF or not.
I don't know is the honest answer.
The only experience I've had of warning lights clearing has been after a fault has been clear for three complete cycles of engine start, warm up, and drive for a while. (Over three days).
That still left a logged error code, but the warning lamp was out.
Whether or not that's universal, or just a FIAT peculiarity, I couldn't say.
The link above by Swiss Tony is interesting - if you register there you can access three pdf's in that link which look like copies of Lexus information for how to get at and test the valve which is probably the cause of the code 1651.
Looks fearsome to get at though:
"damn....17 quid for the new vsv valve....3 hours labour to replace...."
Last edited by: AnotherJohnH on Mon 27 May 13 at 11:30
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Chuffing hell. I should dump it on the Polish ebay and bring another after my holiday.
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Taking 0141 along with the others and the intermittant Lambda sensor warning suggests, er, Lambda sensor.
Pull a plug on both bank 1 and bank 2. If the one from 1 is sooty, swap the Lambda on the exhaust from bank 1.
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>> Taking 0141 along with the others and the intermittant Lambda sensor warning suggests,
>> er, Lambda sensor.
The trouble is we don't have a full set of decoded errors, yet, and the car probably has 4 lambda sensors: pre and post cat for both banks, according to a comment in this thread:
www.clublexus.com/forums/ls430/587849-p1651-error.html
which might be a start with the P1651 error code.
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>>suggests, er, Lambda sensor.
Yes, it's entirely possible - I wouldn't rule it out.
But, as lambda sensors measure the output of the engine, any fault upstream can affect the gases which are in the exhaust downstream.
Therefore, checking faults upstream rather than blindly fitting sensors is worthwhile.
As an example, I think the 1651 code has something to do with a valve in the inlet manifold. If this valve is jammed, then it can affect the fuelling, and bingo!, you get a lambda sensor fault code.
As mentioned, not only is there the possibility of an upstream fault, there are also 4 lambda sensors - if the fault is a lambda sensor, unless there's a common factor, it's unlikely that all 4 have failed. If there is a common factor (anti-freeze contamination?), then, that fault should be fixed first.
Last edited by: Number_Cruncher on Tue 21 May 13 at 13:56
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Could a possible be be a leak in the pipework after the air flow sensor leading to the motor getting less air than it thinks it is?
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Here's another no new parts job which I think is for the correct car/engine/year:
www.lexusownersclub.co.uk/forum/tutorials/article/105-ls430-43-3uz-fe-engine-cleaning-maf-sensor/
Here's a quote from the illustrated guide -
"The MAF sensor is very important to the running of the car as it determines how much air is entering the engine. As the hot wire within the sensor becomes dirty over time the sensor indicates more air is being drawn in than actually is. The ECU, using this data, will start to add more fuel leading to poor idling, poor throttle response, increase in fuel consumption and a reduction in power. "
Seems like a candidate.
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A MAF problem would affect both cylinder banks. That link clearly shows a single induction tract with one MAF sensor serving the entire engine. The fact that all the quoted codes refer to mixture errors on bank 1 only rule that out.
I still reckon lambda as it's one of the perishingly few components that affects mixture and acts on one bank only.
As I said, pull a plug on each bank. If one side is sooty and the other not, it's almost invariably a problem with the lambda sensor for that bank.
If it were me, I'd just change it. If they were particularly expensive, I might swap 'em side-for-side and then clear the errors, run it for a bit and reread the codes to see if I got a load of bank 2 errors instead, just to be sure.
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>>The fact that all the quoted codes refer to mixture errors on bank 1 ...
Are you sure about that?
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Earlier in my post I wrote this:
"I never bothered with the lambda but I know it's part of the MOT test now and my MOT guy sternly wagged the finger at me - 'sort it before next time'"
My MOT guy told me last year that the Engine Management light would be part of the test and that's why I was fretting about that Lambda sensors on this thread. Well I booked the car and spoke to him and asked if the engine management was a fail, he said 'Noooooo, it's not happening this year'
Yezus Christ, all that worrying for nothing. I'd even bought a connector and software to reset the lights on the dash before the test. It's a few hours before the light pops on again so it wasn't a problem either way.
MOT pass.
And I'd had to buy two new front brake discs a couple of weeks ago because of that warped problem. Drives like a dream. Advisory: two rear discs look pitted and scored. Never ends does it...
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Lexus LS430 - 03 4.3 It's lazy - Number_Cruncher
