2005 1.6 Corolla - Mil On - Fault Code P0012 - Any Idea Of The Problem

[thudspud]

Hello

I picked up my new (to me) car last Friday a lovely 2005 Corolla 1.6 Petrol T-Spirit, Got it for a good price as it has done 78,000 miles. After doing about 150 miles in it the malfunction light came on so got really worried, plugged in my reader and it came up with fault code p0012 "'A' Camshaft Position - Timing Over-Retarded (Bank 1)"

I deleted it and the light went off, spoke to a lexus engineer who I know and he said it was nothing to worry about, he has seen it loads of times and it usually happens when they have been stood for a while, mine hadn't moved for nearly 2 months.

Anyway, drving back home tonight after about another 200 miles and it has come on again, same fault code.

Does anybody know what is causing this? Any way to fix it? Is it damaging my engine in any way?

Getting a full service done on it next week.

Many thanks

Chris

[slarti54]

VVTI? Maybe a problem with the advance gear on the camshaft if it's not advancing / retarding properly.

[thudspud]

VVTI? Maybe a problem with the advance gear on the camshaft if it's not advancing / retarding properly.

Thanks, Yes it is VVTI, Not really up on how engines work, more into electronics!

Cheers

Chris

[slarti54]

As engine speed increases so does oil pressure. This forces the cam shaft into an advanced position relative to the crank shaft and improves ignition etc. There might be a problem in the mechanism that does this, hence the retarding error code.

[thudspud]

anybody know anything else about this? It didn't come on for about 1800 miles but has now come on 3 times in a couple of hundred.

Cheers

Chris

[Twincam.GTi]

Check Engine Light Code P0012

Variable Camshaft Timing Over Retarded - Bank 1

This code will trigger the check engine light under the following condition:

The comprehensive component monitor, referred to as the CCM, monitors the Variable Camshaft Timing (VCT) position for over-retarded cam timing. If the cam timing exceeds a maximum calibrated limit or is stuck in a retarded position, the check engine light will come on and thus set relevant trouble code.

Possible faults could be (and I emphasize only could be!)

Incorrect camshaft timing

VCT solenoid valve stuck open or continuous oil flow to piston chamber (-This is what member slarti54 was quite rightly mentioning)

Camshaft advance mechanism binding, or faulty VCT unit

This check engine light code is caused by a mechanical fault of the VCT unit or related components, so there is no need for electrical diagnosis.

Possible symptoms may include rough idle, stall or hard start - HAVE YOU HAD ANY OF THIS ?

Unfortunately to ideally get to bottom of problem (if 'drivability' is bad) you will have refer to manufacturer specific component tests for the VCT unit - in other words... ...this could then mean a main dealer visit - sorry! :(

[Twincam.GTi]

As a side note -

May I ask what OBD2/EOBD code reader/scan tool you have been using?

[Twincam.GTi]

BUMP!

And still the 'member' in question does not respond or inform me of outcome? ...

...why the F$$$ do I bother!

[thudspud]

Hello

Sorry, first time I have ben on here since you replied, been working 14 hour days for the last 4 days so not really had time to get on here and don't get email notifications of new replies!!!!!!!!

The car does have a rough idle which varies slightly so could be something that you have described.

My code reader is a Uiftech Memoscan U581

Cheers

Chris

[Twincam.GTi]

^

No probs about not getting back ... ...sorry it's just last week I helped a few people out and none got back - perhaps it's legitimate reasons (like yours) - appologies once again.

:)

Right - back to problem

The scanner/code reader you have is fine for home use (one word of warning - is it 'can-bus' compliant? your okay with present car you have as it's a 2004 model but after 2005 'can-bus' protocol starts to appear; mandatory by 2008 model year on all cars.).

You say rough ideling - do revs 'burble' between 750rpm - 1100 r.p.m when say sat at traffic lights?

Does car actually catch you out and stall?

[thudspud]

Not sure about the can bus compatability of my reader, it says 'CAN OBDII' of the front of it!

Yes, the revs do 'burble' as you put it, I would say that once the engine is warm it is between 600 & 1000 rpm when you are stood still but it has never stalled.

Cheers

Chris

[Twincam.GTi]

Your okay it IS can-bus compliant! :)

It sounds like it is a faulty VCT solenoid - if so this will need a trip to Toyota dealer, but ... ...I would hope they do NOT change it and fingers crossed - I WOULD HOPE THEY CARRY OUT A PROPER CHECK FIRST!

Also as I mentioned before there can be a continuous oil flow to piston chamber - have you had an increase in oil consumption? - if not it ain't that so no worries there!

Finally as regards the 'burbling' when idling (which I asked about) if it wasn't for the actual code of P0012 I would have been damn sure it was a Oxygen/Lambda sensor on way out - especially as car has done approx 80,000 mile?

[thudspud]

Thanks

Haven't noticed it use any oil to be honest, looks at the same level it was when it last had its major service about 4000 miles ago.

I had read up about the lamda sensor going as, as you say, it has done 85,000 miles now!

Will get it checked out next time it goes in.

Cheers

Chris