Error Code P0136 An P0156

[avensis2003]

my engingelight is burning an i have read the car an it give me those

error code P0136 an P0156 i have already place new sensor an reset the ecu but the errors still showing up an the engine lights is burning again

what do i need to do

[Beagh1958]

To avensis2003,

What model, year, fuel type ( D4D - 1800cc petrol?) is your vehicle. Will try and help if i can.

Regards, Beagh.

[avensis2003]

To avensis2003,

What model, year, fuel type ( D4D - 1800cc petrol?) is your vehicle. Will try and help if i can.

Regards, Beagh.

its a toyota avensis year is 2003 fuel type is gasoline 2.0vvti d-4

[Beagh1958]

To avensis2003,

See PM please.

Regards, Beagh.

[thisman]

To avensis2003,

See PM please.

Regards, Beagh.

Beagh - can you please send me the info as well? I have the exact same problem (2004 model though).

Thank you,

Arnold

[alan333]

From my (limited) info your codes are deciphered as follows. There are 2 listed (dunno why tho)...

PO136 - Heated oxygen sensor (H02S)2 bank 1 - circuit malfunction. Possible cause is - Heating inoperative, wiring, H02S, ECM.

PO136 - Oxygen sensor (O2S)2, bank 1 - circuit malfunction. Possible cause is - Wiring, O2S, ECM.

PO156 - Heated oxygen sensor (H02S)2 bank 2 - circuit malfunction. Possible cause is - Heating inoperative, wiring, H02S, ECM.

PO156 - Oxygen sensor (O2S)2, bank 2 - circuit malfunction. Possible cause is - Wiring, O2S, ECM.

[Jamesbelfast]

I have seen misfiring engines whereby unburnt fuel entering the exhaust brings up the exact fault codes. Fault codes are are rarely definitive but usually a pointer in the general direction. If it were mine I would be checking the colour of the spark plugs first to see if any are dark in colour - signs of poor ignition or incorrect fueling.

The upstream Lamda sensor is usually first to dwtect incorrect exhaust gases and the downstrem unit detects after the gases have passed through the CAT. If the engine is driven with unburnt fuel entering the exhaust it can lead to CAT failure.:)

[thisman]

Thanks for the info guys!

Well, according to the dealership the ECU needs to be replaced - costing me $2,000. They don't seem to think that the current one is broken, they simply said that an "improved version" of the ECU would rectify the problem! :ffs:

[Beagh1958]

To thisman.

The 1st Mk11 Avensis from memory had an ECM unit that could play up (don't have the car anymore) my car was just still within warranty. MIL light kept coming on giving codes suggesting faults as follows, faulty ECM, ECM wiring circuit & Lambda sensor. As pointed out above, code reasers do not fix cars , they just hopefully point you in the right direction.

I was in the trade at the time so i new a bit before tackling local dealer. They tried every trick in the book to get out of changing ECM free of charge under warranty, more of that later. I insisted upon receiving a diagnostic log to show ECM was at fault, they said they could not confirm if i had any other fault with out renewing old ECM. I had already confirmed that ECM was at fault which was playing havoc with the pre-bank lambda causing over fuelling which resulted in dead cat.

So i had a new ECM fitted, which i'm certain was an upgraded unit as Toyota have suggested to you, brand new lambda with cat as well, problem solved.

Had to fight for it, but all done for free under warranty in the end. That being my first bad experience with a Toyota dealer ever.

Regards, Beagh.

PS: Nearly every car we had into the garage at the time would have been a year or two old at the most, so all under warranty. This is the bit that confused me with Toyota. To my knowledge any part that fails under warranty if proved via manufacturers testing equipment & backed up via diagnostic log ie: reams of paperwork, this would entitle dealership to a certain amount of money back against failed part. If anybody knows better i will stand corrected.