NewHilux.net

Hope this is the right section.

I have a Mk6 2009 3.0l D4D.

My Hilux lay idle for about 4 months during which time the battery died completely (I mean dead as a dead thing for probably 2-3 months). On getting everything going again, including a new battery, the malfunction indicator light came on immediately after starting the engine.

I plugged in my OBD thingy and got the code 0069 (barometric pressure correlation). This is the same code that came up a few years ago, and the fault was caused by a blocked MAP filter. This was cleaned out and the malfunction light on the dashboard cleared on its own after driving down the road.

Considering that the pick-up was fine prior to being laid up for a few months, I find it odd that the same error code has popped up. I checked the usual suspect areas - dirty air filter and MAP filter and associated tubes again - and all good.

So the question is...

...is it possible for the computer, after being deprived of power from the battery, to get its knickers in a twist and throw up an old malfunction code? ...and if so, is it okay to clear the 'fault' via the OBD?

Cheers,
Buttface.

Yes it is entirely possible as the ECU stores codes until they are cancelled. Although a dead battery tends to cancel everything, the code may still exist for some reason. I don't know if you know that codes are stored as 'pending' for a period without showing the malfunction light, until a certain number of times the code is produced, then the malfunction light comes on. There may be some residual codes 'pending' which could be your problem. I suggest clear the code and see if it returns. Hopefully not but if it does then you know the drill, follow the code.

Thanks Gipsy,

I'll clear the code and see what happens.

...and I did not know that the ECU stored the codes as 'pending'. Good to know.

Cheers,
BF

If you check your scanguage you will see codes and codes pending as separate selection. If you check pending first it may show the codes that have not yet set the MIL light.

Gipsy wrote:If you check your scanguage you will see codes and codes pending as separate selection. If you check pending first it may show the codes that have not yet set the MIL light.

Thanks Gipsy.

I used a different (but limited) OBD software and it's come up with a couple of extra DTC's - P0102 and P0113. No pending codes. It seems there might be a genuine issue rather than one caused by the dead battery affecting the ECU. Judging by the codes, I'll give the MAF sensor a clean and go from there.

Thanks again.

Cheers,
BF

Update (2 hours later): Huh! MAF sensor not that dirty, but dirty enough it seems to throw up the DTCs. The engine light disappeared as soon as the ignition was switched on. All codes cleared by themselves.

I guess the moral of this thread is never assume coincidence doesn't happen.

Thanks once again Gipsy for your input.

Cheers,
Buttface.

What repairs can fix the P0113 code?
Repairing or replacing the IAT connector short. (Intake air temperature)
Repairing or replacing the wiring short as necessary.
Replacing the IAT with a new sensor.

P0102 is the general code for a problem with the Mass Airflow (MAF) Sensor having a low voltage output to the Engine Control Unit (ECU).

these are both in the air filter and usually cleaning the sensor with maf cleaner will fix it. Don't touch the sensor though just use plenty of cleaner sprayed on.

Gipsy wrote:What repairs can fix the P0113 code?
Repairing or replacing the IAT connector short. (Intake air temperature)
Repairing or replacing the wiring short as necessary.
Replacing the IAT with a new sensor...

Thinking about it, the IAT sensor fault is an odd one.

I've been for another run, and the engine light did not come on (and no physical manifestation of said codes). I don't have the means to clear the codes (limited OBD software), so can't say if they're old or new. I'm wondering if the mere disconnecting and reconnecting of the MAF sensor 'reset' something in the ECU, untangling its knickers so to speak, after a lengthy period of no battery power, although I can't see how (I reserve the right to talk absolute rubbish with regard to this ). It's the only other action I took other than removing the MAF sensor itself and cleaning it. I shall keep an eye on it.

I haven't been able to test the MAF sensor connector as it's properly sealed up; any attempt to access the contacts will knacker up the connector, which will not be a good thing.

So, yeah, no, dunno...

...and yep, the sensor was squirted with electrical cleaner without touching the sensors.

Cheers,
BF

It's complicated but simplified, the ECU stores pending files, the codes are generated during ECU checking cold start to running temperature and if a fault is found its stored until a certain number are stored pending and then the MIL comes on. The cold hot cycles is where the ecu checks for faults depending on what the fault is. So if it's a less important fault then it's stored as pending until the fault is generated again, and so on until a threshold is reached, then the MIL lights up. In your case, the MIL doesn't light up in that particular cycle because it's sent to pending. Other more crucial faults light the MIL without going into pending.
Hope this makes it a little more clear. Marvellous things these ECU and other electronic devices. Clear as mud!
Get yourself a Bluetooth obd and it allows you to check and clear codes.. all for around $10. Just google Bluetooth V2.1 Mini Elm 327 OBDII Scanner OBD Car Diagnostic Tool Code ReadeT3O they're only $12 Australian stock

Check out the fusion obd app.
I havent used it in years and it was good then, should be a lot bettet now.

Thanks Gipsy and Martyn.

Sadly, I don't have a PC with bluetooth, and I don't own an Android/iphone so not an option. In the past, I have tried installing Bluestacks on the PC to use an android OBD but despite allowing an USB hook-up, the OBD apps have never worked. Tried again today with a bunch of downloading and wotnot, but same story. Hey-ho!

Anyway, not to worry too much as I only really want to clear the codes.

I keep an eye open for a PC-base OBD software that allows code clearing.

Thanks again

All the best,
BF.

Ok techstream gives you all the Toyota diagnostics and runs on a PC or laptop if you have one. Even older laptops can use it so if you don't have one I'm sure you could get an old redundant one from somewhere, else a friend with an android phone?

It's all here

viewtopic.php?t=16394

Gipsy wrote:Ok techstream gives you all the Toyota diagnostics and runs on a PC or laptop if you have one. Even older laptops can use it so if you don't have one I'm sure you could get an old redundant one from somewhere, else a friend with an android phone?

It's all here

viewtopic.php?t=16394

Hah! Just been going through that thread before seeing your message. Talk about coincidence!

Yep, I'll go that route. On top of that, it's about time I learnt more about ECU's and what-have-you (I'm feeling pig-ignorant at the moment - not something I'm revelling in).

Thanks Gipsy.

Cheers,
BF.