2.0 Hdi Mk3 Dispatch / Expert P0299, P1496, P1497 and U1218

[tmead]

Ok - dont feel suckered in here - its actually a Toyota Proace, but thats just a rebadging exercise. VIN is YARXUAHZ8DZ039172, which I think indicates an AHZ variant of the DW10 2.0 engine.
Driving last night at 70 on the dual carriageway with cruise on, all of a sudden had a beep and the cruise dropped out. orange light and a dash warning. nothing specific. Engine power was reduced, but enough to drive home.
Code read indicates P0299, P1496, P1497 and U1218 on diagbox. Seems odd, that I can see a 1496 and 1497, as one is underboost and one overboost. Might that be indicating that the turbo vanes are stuck ? That sucks - its tucked away low down at the back of the 2 litre engine. Looks like I'll be trying to get it on the ramps and have a poke underneath someting soon. Simple fixes seem to point to electrovalves, but I can't find any on this engine ! Previosuoly on the 2 litre RHR they were either down below the alternator or over the back of the timing belt cover.

I'm not sure about U1218 ? that seems to be telling me that the BSI isnt talking properly ? I've noticed a strange clicking under the dash when the engine is at low revs, either immediately after starting or when chanigng gear. Sounds almost like a relay clicking on the BSI - might this be related? I was going to look into this when i had a moment !

[RichardW]

What does the data say when it set the code? What does the live data say now? I found a thread a while back which was similar, but doesn't look like there was a resolution: viewtopic.php?t=69548

[tmead]

Thanks Richard, I'll try and grab some live data, but life is a little chaotic right now. May need to be tomorrow !

[tmead]

Right, even though its baking hot, I've had a little time to investigate. Heres traces after the fault was cleared, on a brief run up the road out of the village.

This all seems to make reasonable sense, and I think indicates the turbo vanes are moving when commanded ?

You might need to zoom in on the images to see the trace I'm afraid - sorry !

[tmead]

And then I tried another run, and the fault popped back up. It was at the last 1/3 of these traces I think. I can't quite understand why this is different ?

[tmead]

I dont have time to put it on the ramps and poke underneath - or energy in this heat ! time for a cold beer and BBQ I think !

[PaulC5]

Look at live data from the MAP sensor and see if its values are reasonable and that it responds as the accelerator pedal is pressed. On our C5 the MAP sensor was bunged up with oil and sometimes gave P0299. After replacing this seemed to stop for some time but did appear again a couple of years later so might have been bunged up again..

[tmead]

thanks Paul, I'll give it a go !

[tmead]

Hi Paul,
just having a think, and the turbo pressure signal in the traces i captured is from the MAP I think ? It seems to follow the reference reasonably ?

[RichardW]

It looks to me like the turbo vanes might be sticky. Put the traces together and added a line where it looks to me the problem might be.

See the turbo position request drops right off, but repeat doesn't. and the boost pressure reference drops a bit, but the turbo pressure goes up. Did you stab the throttle and then lift off suddenly?

[tmead]

could have been a gear change. I stood hard on the throttle to get the largest changes on the traces. perhaps a little too enthusiastic....

Interestingly, no fault codes stored, despite having a bing, and error messages on the screen with limp mode ! Quick pull over, key off, restart and it was fine again. Its been fine for a few trips over the last two days totalling about 50 miles too. Bleedin' typical - we're off in it for a campervan trip to northern Germany and Denmark in a few weeks, so I'd like to find something that is the cause !

[tmead]

I've had a chance to get underneath and take a look now. The turbo actuator moves smoothly through its stroke, although its quite a shove to get it all the way. Theres a bit of a wierd mark on the actuator shaft where it comes out of the diaphragm chamber, but nothing too crazy.

further local driving hasnt triggered the error again. Fingers crossed that continues - several long journeys coming up !

[tmead]

Well, that's a relief. Around 2K miles to Denmark and back, and only one more error thrown. We had a P1497 on the autobahn, when I got stuck in the right lane behind a lorry and had to back off, wait a bit and then drop it down into fourth to accelerate round a lorry, not wanting to spend too long in the left lane. There was a bing and it dropped to limp mode, but almost instantly the fault must have 'cleared' as the EML was not on. Limp mode cleared with ignition off/on, but the cruise was not re-enabled on the first key off/on. I think it toook probably two more restarts before it was re-enabled.

No other errors from the turbo on the trip - I'll start another thread about the irritating clicking noise from under the dash !

One option is to ignore it unless it becomes more frequent, second is to try an oven cleaner turbo clean.
I dont relish trying to access the turbo from underneath and squirt in corrosive chemicals, so am leaning towards a wait and see approach !