Yaris fault???????

[StuartM]

Hello all.
I have been experiencing a problem with my 1.4 D4D TR since new.
Frustratingly, returns to the dealership have not provided any kind of explanation.

The "problem", if it is a problem, is cyclic. For the first 6 or 7 months, about every 300 miles, usually per tank of diesel, the instant economy figure drops, it will not get above 50 mph, whereas it would be running happily on A roads at 75 mpg. This phenomenon will last for exactly 15 minutes and has the effect of reducing the overall mpg figure, for the fuel used to date, from maybe 70 mpg to possibly 59 mpg.
The other symptom of this problem is increased engine idle speed, up to 1000 RPM from the usual 950(?).

Despite a couple of returns to the dealership, I cannot get any explanation for this fault.

I had it serviced recently, and the cyclic event is now occurring every 200 miles! Plus, the service light developed a life of its own, and decided to light up sporadically.
Again I returned the car to to the Dealership explained the problem, complete with emailed explanation.
They found that the oil had seemed to have been over filled (or increased somehow) drained and refilled it & asked me to try it for another 500 miles.

It is no better, the diesel guzzling continues in the 200 mile cycle.

I had a D4D Auris for 3 years prior to this, no such problems with this car.


Can anyone please throw any light on this, before it drives me completely mad???

[Foot]

I always thought if the light comes on they can get the code and try to correct the problem. With the oil increasing I do not know enough about motors, only thing I can think of is water coolant getting or gas, but that should be easily seen if that was the case in the appearance of the oil.

[StuartM]

Thanks for the reply foot.

The spanner light coming on didn't provide a fault in the diagnostics, the just kept resetting it until eventually they replaced the oil to the correct level.
Since then the light has kept off.

I don't think there is any ingress into the sump oil, I am more inclined to believe they over fllled it during the service. They asked me if I had topped it up at any point, but I hadn't.

What I am really trying to find out if anyone else with a 2012 D4D Yaris TR is experiencing this diesel guzzling cycle???????

[CTScott]

For the high idle behavior, the nine items below are what the service manual for the D-4D lists as potential causes:

1. A/C signal circuit -
2. Injector
3. Cranking holding function circuit
4. ECM
5. Supply pump
6. Fuel pressure sensor
7. Pressure control valve
8. Engine coolant temperature sensor
9. Fuel temperature sensor

You might want to invest in a code reader, so you can read the codes when the light comes on, particularly if what is causing it is intermittent.

[StuartM]

Thank you Mr Scott!

You would think the dealeriship wold have given me a hint at these possible causes.

I think you are right about the code reader, but I have never seen a fault light illumiated. The dealers told me there we no faults logged, but I think I will check myself.

Also, although intermittant, this problem is cyclic - originally about every 300 miles, more recently closer to every 200 miles, since the service & overfilling of oil.

We seldom get that kind of snow here, by the way, love the snow plough!

[why?]

so have you checked to see if it is just the mpg computer, or are you actually getting worse mpg?

The other question is what type of transmission do you have? Does this happen randomly when you are driving, or at start up only?

[inno]

what you describe is a DPF regeneration. ist should only occur every 400 miles.

[manakorin]

So it basically keeps on repeating itself in a particular period. I see.

[CPO]

The way I understand DPF's (diesel particulate filter) work is that they inject fuel into the exhaust at a given intervals to burn off the soot in the filter. The ash falls to the bottom of the filter and eventually the filter will become clogged and need to be removed and cleaned or; in a VW TDI's case, replaced.

[Yaris2005og]

sup bro do you guys know where the starter solenoid wire is in the toyota vitz 2005 push start keyless?