euro4 Lambda and EGR DTCs

[A lex]

A month after changing both the DPF temp sensors, the yellow triangle of doom reappeared on the dash today. Luckily no limp mode.

Fault codes are:



Economy has been a bit poo lately, gearchanges a bit sudden, and it sounds a little rough sometimes at idle.

At the end of the month we have a 5k euro tour coming up, so cant afford to be fannying around with it too much - a quick and permanent fix needed.

Im thinking replace the o2 (lambda) sensor as a first fix and take it from there..... sound reasonable?

[5cilinder]

I think the yellow color implies that the dtc's arent active at the moment but where in the past.

Some codes need a clear drivecycle to clear the faulthistory so wait a while
Those faults could be generated with a hickup in the canbus communication

If the faults become active again (red) you can ( i see you have vida) under the advance tab in the ecm calibrate the egr valve and the oxygen sensor with the vtc 2000 symbol
Also those sensors could be on the same fuse ,check that too specificly if the faults have the exactsame timestamp , you can also check with the same vtc2000 symbol the altenator charge function (you see that also under the dtc's),if thats messed up it can generate "faults" in components wich arent faulty due to the voltage disturbance in the canbus communication

[A lex]

The battery on the car is slightly weak (5 years old and I sometimes get 'low voltage warnings' if I leave it parked up with the radio on for a length of time).

Sensible to replace the battery too?

[5cilinder]

Those faults present themselfes only when the engine is running ,and then the altenator should provide a healthy voltage even with a weak battery (if the altenator is ok)
So a "weak" battery isnt a problem if the car starts ok , keep using the battery until it isnt sufficient anymore
i use a solar trickle loader wich delivers 0,1 amps when sunny costs 10 euro's or so , extends batterylife in general .
A good battery& good care could go on for (way)more than a decade

When you use the radio when the engine is off make sure you set the key on 1 in stead of 2 that switches on more amp consumers like the primerpump

Make sure the altenator is ok if those voltagewarnings come early ,you can test in vida too

[A lex]

Had a chance to play this afternoon; some observations:

- It didnt produce the fault whilst I was live monitoring it - typical!

- Alternator function tests as OK (but only just), which suggests the battery has seen better days. Quite happy to be changing that tomorrow.

- DPF had 18.5g of soot, which is just below the 'cruising burn weight' according to VIDA. Nothing to worry about there. I did a forced regen anyway, and took soot down to 10g.

- I re-initialised/calibrated the following:

DPF pressure sensor
MAF
EGR position sensor
(and another one I forget!)

So a new battery tomorrow, and then drive it to see if the fault comes back in the next few days. Having seen that the DPF only had 18g in there, im not overly worried about is functioning now.

[5cilinder]

Save your money, these faults arent caused by the battery
The altenator test has nothing to do with the battery
Batterycondition can be established with a battery capacitytest (measuring internal resistance while unloading)
But even if the battery is not 100% it will not cause the faults

[A lex]

Originally Posted by 5cilinder

Save your money, these faults arent caused by the battery
The altenator test has nothing to do with the battery
Batterycondition can be established with a battery capacitytest (measuring internal resistance while unloading)
But even if the battery is not 100% it will not cause the faults

Alternator test in VIDA can indicate the condition of the battery (to an extent).

The battery in the car is old and im happy to replace it. End of.

[cheshired5]

Originally Posted by A lex

Alternator test in VIDA can indicate the condition of the battery (to an extent).

The battery in the car is old and im happy to replace it. End of.

My battery is as low as yours (13 year old original) but I literally use it just for starting the car.
I don't blame you for changing it if there's any chance of accessories being on with engine off.

[5cilinder]

Originally Posted by A lex

Alternator test in VIDA can indicate the condition of the battery (to an extent).

No it cant
Besides a bad battery has high internal resistance and takes less amps from the alternator in stead of more amps like a good but drained battery

Originally Posted by A lex

The battery in the car is old

It isnt old with 5 years

Originally Posted by A lex

and im happy to replace it. End of.

If the placebo feels good go for it

If you didnt do a battery capacity test you wont know the battery is bad , besides you could have a short circuit somewhere wich drains your battery anyway
Better check those 2 things first before jumping to conclusions or keep changing batteries when a short circuit keeps wrecking them slowly

[A lex]

Todays progress:

Changed battery.

Did an aerosol EGR clean (not for the faint of heart, but seems to work well!)

Cleaned the electrical connections on the ECM and the HO2S.

Even if it doesnt fix the glitch ive been having, it was worth doing the above as its now driving much, much smoother.

(Before changing the battery I left the IGN II on to see how long it would be before the 'low voltage' warning. No accessories were powered, radio off etc - it took 7 mins! So in any case it was time for the battery to be replaced!)

Ive got to commute in it tonight, so im mildly curious if the triangle of doom will return!