R3KogHyZe

Hey guys my 1.6iSE runs fine for days/weeks then CEL comes on

Engineer pulled this P0135 code I have now bought DashCommand so I can monitor myself !

What would be recommended course of action here please ?

Engineer suggests replacing the part - however at £225 for Honda part and apparently a lotto with 3rd party is it possible to diagnose the heater before assuming it's faulty ?

My understanding is the heater element engages on cold start for emissions regs - O2 sensor should report OK when car is at temp. Is this correct and therefore safe to keep clearing this code ?

I've also noticed a lack of vacuum at the petrol cap when the code comes up - but P0135 is what it says

Cheers

ezone

P0135 in a US car is O2 sensor B1S1 heater circuit failure.

The current used by the heater is monitored by the PCM and it codes if the amperage is outside its specified parameters.

To get really accurate, I think one would need to monitor the circuits involved with the code and be able to see what happens at the exact moment the code sets.

This would probably mean connecting a pair of voltmeters and maybe an ammeter, and driving until the code sets again and seeing what the meters are doing.


Most of the true heater failures I see are not intermittent nor random.... so I might suspect wiring issues, or maybe a sensor that has already been replaced with a unit that is not OE (incorrect resistance of the heater element).

R3KogHyZe

Thanks Mate

Sensor is original with 75k on the clock.. You suggest monitoring of the O2 sensor - if I follow correctly - because if it's not continually throwing up the heater fault code the heater circuit cannot be stuck open or closed? Otherwise I'd be checking the resistance on the heater circuit.

I've done another 100 miles since and P0135 hasn't come up again.. I haven't done anythng but gently move around the O2 cabling whilst inspecting it and checked fuses and cleaning their contacts. Car seems to be running good, in fact - maybe TOO good. On ignition it idles straight to 1500rpm and gets to temp (and stays there -rock solid- 1/3rd of way up scale) VERY quickly .. like under a mile of driving on a cool day. Maybe it's meant to be like this and it's good design, but my Golf would take lot longer !! Could it be running rich? I'm monitoring fuel consumption now.

Dash command seems to be a double edge sword to someone like myself who is learning... there is so much information I don't understand. But since I have started, I saw the following values at idle, now I believe the long values should bounce between like +/- 2% and short more but well under 10%. The ECU was last reset 100 miles ago.

SAE.LONGFT1
SAE.LONGFT3
SAE.SHRTFT1
SAE.SHORTFT3



To be clear aside from the P0135 code coming up car feels lively and isn't throwing up any other codes.. also I have OCD I continually find stuff to worry about... , but please can you say whether the car should be OK to drive for now ?

Oh here is the exhuast btw.. I don't have the tools to pull spark plugs atm

ezone

Leave it alone, continue to drive it and see if the code returns.


All the data you see:
as long as there are no codes setting and no running problems noticed as you drive, you might assume whatever you see is ok (unknown scanner app might not interpret raw data 100% accurately so beware.)

R3KogHyZe

Thank you ezone

That makes a lot of sense.. and probably good for my health too

I'll unplug the reader and keep an eye on mileage..

Not going entirely off the gauge though! These Honda ones seem a bit up and down..

R3KogHyZe

And there it is again.

P0135

Cleared the code and drove home.

Gutted.

What next?

You were right about the fuel trims. Not sure where the figures are drawn from in the previous post - I found the default ones - and they seem a lot more sensible.

ezone

How long did it take to turn the light on after you started the car? 5 seconds? A full minute?

Check engine light stayed off during the trip home?

?? Not familiar with the term, what's that mean? Sad/depressed?

You could throw a sensor at it, but that's an expensive guess.
The fact that the failure is so intermittent kind of makes this a guessing game.
If you cannot test during a failure event, you probably will not pinpoint a problem.

If you clear the codes immediately after the code set and drove it home without incident, that indicates the failure window is very very short.



Ohm test the primary sensor heater circuit wires (the pair of wires with identical colors)
compare to specs (or a known good sensor)?
I have no info for non-US cars here.


What is the brand name on the primary O2 sensor in the car now?
Any idea if this sensor is original or has it been replaced at some point?

R3KogHyZe

Yeah it's throwing the code quickly on startup... this time I'd been for a short run, then returned to the car after about 30mins. Turned ignition 20 seconds later..

Once fully warmed doesn't seem to come up.. so far.. and given it's just P0135 occuring, seems to point to actual heater fault rather than say intake leak would you say? At 75k on clock, about right time to fail.. and I presume this can be gradual..

The other thing I've noticed though, everytime triggers it;s been very humid / raining / muggy .. and the wiring didn't look brilliant.. I'll take a very close look tomorrow ! Will test for ohms as suggested ..

Sensor is original .. OEM is 5x the price of 3d party where I am ..

ezone

So you now have established some sort of pattern to the fault.
By definition, it is a fault in the heater circuit. Whether it is the sensor, wiring, or whatnot is yet to be determined.
How so?

Figure out what and how to test first...,, then set the car up so it will fail as described in the first line..... Test the sensor while it is at the temperature you expect it to fail.
The part through HONDA is 5x higher. 3rd party could net you an actual correct part if you know ahead of time what they are selling (most clerks can't help with that though, so YOU have to do the research and legwork first)

Like I said earlier, see what brand the sensor is. (DENSO or NTK)
Then look up that manufacturers website, look up their part numbers, then figure out how to get it to your door or what to ask for at the parts store.

This is how you get OEM parts cheaper. The OEM for the sensor is either Denso or NTK, not Honda.

ezone

Got a good wiring diagram yet? Where does your O2 heater get its power from?


I have a (relatively) low mileage 09 in my bay with codes P0135 and P0498, both items receive power through to one of the relays, relay intermittently does not pass power through the contacts and causes the codes.

R3KogHyZe

Very encouraging to hear the OEM may be available elsewhere .. will probably get a trusted tech to remove the part to retrieve part number because, as simple a job as it may be, I'll probably mess it up somehow like sheer the thread off or split the manifold..

I hear Denso recommended on the UK Honda forums so may ask if they know the exact part for my engine type .. these guys are frequently recommended http://www.sparkplugs.co.uk/ and if I drill down through my car details to engine D16V1 I get this which in all probability is the right part http://www.sparkplugs.co.uk/denso-ox...ensor-dox-1453

Worth exploring the relay/fuse angle - I read some people have replaced their O2 and discovered it was fuse.. sadly nobody specified which fuse it is and I cannot discern from the manual I had a link yesterday which I THINK was for the wiring - I'll find it somehow.

Looking again the O2 wiring (I hope I'm looking at the right one).. may not be bad, just don't like seeing wires exposed like this would be good to see them in a shroud of some sort or taped up for protection.. can't access for inspection



This bit to the engine cover doesn't look too clever IMO I think I'll get a bit of electric tape round that..



May I thank you again for your encouragement and assistance

ezone

Regardless of what brands you hear recommended, figure out what the factory installed and use that same brand.

Markings could be on the hex, the ring above that, or on the shell. Cleaning with a wire wheel is usually necessary

Example (NTK brand):

ezone

The wiring pics you show look kinda average IMO, not alarming. They aren't always fully covered.

R3KogHyZe

Looking at the one to the right, I would never have guess it had writing on it and to use wire wheel.

I'm learning TY.

It will also show the part no on the body, right, so I can literally ask for identical ?

P0135 is expected now and today catalyst monitoring, oxygen sensor and EGR system monitoring have become incomplete.

Went to my one trusted mechanic, but hes always so busy I have to 'book it in' to discuss..

He IS good though, that's why he's busy. So I'll book it in and hopefully he'll diagnose .. just want to make sure he's happy to gets the exact part.

Meanwhile I've checked fuses for continuity, and over the weeked I'll figure out how to check the relays, the resistance on the O2 sensor, and how to raise cash for parts and labour

ezone

The markings on the sensors aren't always catalog type part numbers, so no.

Figure out the brand, then go that makers website and look up the sensor by application (enter your car info) if you want to go that route.

emich

Hello
Is that an image from application on your smart phone?
Is it foe android what's the name?


Looks great
Please share
Thanks

R3KogHyZe

Hi Emich

Yes - that is on an iPhone 4S though.
I'm using an OBD-II wifi dongle suitable for iphone (see )
You can use a Bluetooth one for Android
The software is DashCommand (here) which runs on Android too I think..

Together they cost me £22

For Android you have more choices though..
Torque is the most popular one and may be even better

I was going to update this thread ..
P0135 popped up intermittently
I confirmed it's just P0135 using the above tool and cleared the code a few times
I checked all the fuses they were fine
Swopped a few over (same rating obviously)
Since then .. about 2 months ago.. The code hasn't appeared

Not sure what's going on..
It's a bit warmer in the UK, so I'm wondering if there's some wiring fault affected by humidity
But since the code has not reappeared I've put it on the back burner for now

emich

Thanks
I have similar problem
Both sensors don't get ground. For some reason I am getting P0141 only for the downstream sensor. The ECU could be the problem I found burned resistor on the motherboard.

R3KogHyZe

Quick update to this thread.

To recap was getting P0135 error with no other codes and no major performance issues.

Well that changed and gradually the car become more difficult to drive in the lower gears. It was becoming hard to find the biting point. I continued driving as I didn't have the money.

Took it in to have the MOT done and code / sensor sorted. The car failed on emissions which were 'wildly out' and pointed directly to the Lambda sensor. This part was changed it passed emissions and has driven well since.

I had been thinking the car was fine to drive as it's only the heater for the sensor and as that warms up quickly it doesn't matter. What I've learned I think is that the heater failure was symptomatic of deterioration of the sensor overall, and codes do not necessarily trip when a components performance drifts.

Thank you very much for the advice contributed.

ezone

The sensor does not work as designed until its internal temperature reaches an extreme temperature, in the neighborhood of 600-1000*F.

If the heater is bad, it (the sensing portion) doesn't work right and cannot until or unless the exhaust can get it hot enough to operate. If the sensor is located someplace away from the engine, it's difficult to get it hot enough to work just by heat from the exhaust stream alone.

If the sensor isn't able to accurately report fuel mixture to the computer, then the computer has no way to accurately regulate fuel injection delivery (cycle is known as feedback). The computer has to rely on a preprogrammed 'base fuel delivery map' if it has no feedback from the sensor.

HTH

R3KogHyZe

Does help - thx for filling in the picture (you're a stalwart of this community !)

I probably took to heart some fluff on the internet about the heater element being an overzealous emissions measure, doesn't matter as the car gets up to temp quick. An engineer I have now abandoned actually suggested I ignore the code even at MOT time, which didn't sit right with me. The car was borderline undriveable by then and it never did throw up any other codes..

ezone

Thanks.

Not if you understand the how and why.

An unheated, single wire O2 sensor relies on hot exhaust to heat the tip (sensing portion), which could take several minutes, and if the sensor is located far enough away from the engine it may not reach activation temp unless it's being driven for a while.


Most of the time you would see a single wire sensor placed extremely close to the engine, but not all designs did.
I've actually witnesses distant mounted unheated sensors cool off and become inactive as the engine idles.

Engineers want the computer to be able to control fuel as quickly as possible in order to get emissions minimized as quickly as possible, and a good working heated O2 sensor can become activate in as little as 15 seconds.


See above.
Temp of the exhaust and O2 sensors has very little to do with coolant temperature and the gauge on the dash.


Engineers can be pretty smart people.....and at the same time, I want to kill many of them.
Your engineer probably doesn't specialize in the automotive fuels and emissions fields though?