rey_winslow

On the way home from this afternoon I saw the Eco button wasn't enabled, it was fine this morning. So I figured that the battery was the issue. Until I got to the stop light and had rough idling, hmmm. Maybe not being able to get into Eco was the culprit I thought. Popping the Launch into the port I got this:

Not quite what I was expecting.

CaliBenzDriver

These faults have status STORED for now. Cyl.4 is starting to mature. Make sure you're running good clean oil... not 10kMi as 'factory recommended".

ECO tracks the battery charge level to adjust the ALT Voltage.

rey_winslow

Thanks Cali, the last oil change was about 10 months ago so maybe 5k miles, The battery voltage was 11.87 so I'm going to replace that this morning and see what transpires.

JettaRed

iTrader: (1)

And TURN OFF Eco mode if it is the Start/Stop feature! Not good for the engine and a stupid way to try to save fuel. If by Eco mode you are referring to a transmission setting, then that is different. There are ways to disable Start/Stop using Launch if you search these forums.

rey_winslow

Thanks Jetta, yes I'm talking about the Start/Stop feature. I was looking at DFWdude's post on that last night, will try it today.

rey_winslow

New battery in and we're back to normal operations, Eco button is on and no more rough idle, diagnostic scan saw no ECM issues, there are some others I will ask about later.

Thanks folks!

CaliBenzDriver

You can do yourself a favor by reading the car voltage while driving... above 12.6 but not below 12.2 while driving.

See what range of currents are shown.... lower is better.

ECO stands for "Engine Cut Off".
It's the engine "start/stop" feature.

rey_winslow

Well, I thought it was fixed but this afternoon on the way home I got the same issue. It was fine yesterday and this morning but not this afternoon so not sure what to check next.

CaliBenzDriver

... what to do next is track battery sensor on IC Display while driving.
You need to know if this is discharge while parked or low charge while driving.

Either way that can leads to experimentally unplugging ALT-LIN control.

That chaos serve as witness of poor CAN-C networking with ESP + CGW for which chassis REBOOT is a temporary fix. Same exact thing thats screwing up our smooth TCU shifts.

rey_winslow

Thanks Cali. What specifically am I looking for on the display? I understood part of what you said but this will be a learning experience for me.

CaliBenzDriver

> BATTERY DISPLAY:
-- The IC Display shows battery voltage plus charge or drain currents.
-- Positive currents are battery charge
-- Negative current is battery drain


> GOOD VALUES:
-- The voltage will range from 12.6v to 14.9v according to engine computer control.

-- The current should be less than 25Amps and mostly near 10Amp decreasing.


> BAD VALUES :
-- the voltage swings below 12.4V... 12.1, 11.9V... while driving

-- Currents are higher than 35Amps are guaranteed battery drain issue


> TEST RESULTS:
-- Battery should never see voltage below battery charge value of 12.5/12.6V..... NOT 12.1V!!

-- When charge voltage is switched from 14.x down to 12.6V the battery is used as a capacitor to supply "surface voltage" ... is totally expected.

-- Battery charge controlled by soft-crashed Bosch ECU control may swing below 12.3v with high drain currents greater than 30A up to 90Amp.


> QUICK FIX:
-- This is easily reset with "key cycle" while parked.... stop, lock then unlock, restart!

-- Headlights ON does that very well also.

rey_winslow

I tested the car this morning, did my route to work and home, voltage was ~14.8 and amps were ~22, I didn't see any current near 10 amps. The car ran fine, no rough idle until I got to the same spot where it happened the previous times, very strange. I get home, turn car off and on, quick trip around the block and no rough idle, not sure what to make of it.

CaliBenzDriver

When evaluating charge system, you need to note current can be negative for drain or positive for charge.
Nothing wrong happen today... stay at it.

Restarting the car reinitializes the charging system. Use this info to your advantage if car begins to drain battery below 11.xV while driving, the park to restart.

If you do this while testing then nothing's going to happen. The CGW needs time to trash COM's between ECU and R-SAM through CGW.

rey_winslow

Current was negative before start, but that's the only time.
I'm not sure I'd say nothing wrong happened today, the engine idled rough and I didn't see any drain on the battery when it happened.

Thanks Cali.

CaliBenzDriver

You're getting rough idling with normal voltage being supplied and have seen misfires codes detected.


How old are your ignition components:
plugs + boots + coils?

rey_winslow

They are still original, only 39k miles on the car.

Rickman30

Did the codes for misfire return?

rey_winslow

Yes they did. Again, driving to work this morning, ~10 minutes no issues, driving home ~10 minutes misfire happens @ ~9 minutes.

CaliBenzDriver

Rick, what do you think is misfiring??


40kMi is really a low mileage for new plugs.
Your 10mn home/work commute trips are super short. Hardly time to fully warm up to operating temperature.
How often do you replace the oil ??

If this V6 NA has been ingesting quarts of thin oil you may have dirty lambda giving you lean misfires.

Use the scanner to read the LTFT's at warm idle.

rey_winslow

Oil change every year usually about 5k miles. I'll try to get the LTFT reading tomorrow.

CaliBenzDriver

What happens is the crankcase ends up loaded with condensate that oil needs to work with.

Twice a year schedule would be better... so long it's not the corner shop 10w30 special and much sooner than every 10kMi.

Presumably your lambda sensors and cats are coated with residues, namely ZDDP/Calcium ashes from "approved oils".

To prevent that condition, your best advantage is to use a lubricant API Rated "SP" in the 0/5/10/15W-40 grades. Modern oil have the latest additive package with more Moly/Boron and half the ZDDP/Calcium for GDI engines.

Until the pendulum swings back towards new nano ZDDP, the "SP" lubricants are being well reviewed. Who ever found a way to blend in all these mollecules is now printing money.

Heavy duty oil are those able to hold viscosity without concerns... with cost-efficient HDEO putting up with short leaved viscosity "to save gas" is now a choice.

Rickman30

Since restarting car turns fuel injector back on. I’m going to say electrical, either coil is weak, or injector itself is failing. But I’d want to verify wiring integrity first. A 4channel scope would bring much to light to the diagnosis. I’d scope the coil, injector, and crank position sensors. Depending o what that produces will help either verify integrity or not. You will need to drive car normally while scope is connected till the problem happens in order to know if it’s one of these or not. I would look at fuel pressure, from both pumps, ensure pressures are within range, again while driving and during fault.

Check for rodent damage, chewed on wires. I would also do the two oil change flush, DO NOT USE ENGINE FLUSH IN THESE ENGINES!

Verify Powers and grounds, by voltage drop tests. Cali can explain the ground situation we all face.

As far as yo yo alternator annd ECO issues, when what ever the PCM is fussing about happens the associated cylinder injector is disabled, hence the rough running, but returns to smooth on restart. The yo yo and eco functions are all disabled including the oil pump solenoid as well during the fault.So don’t waste time on that, once the underlying cause of what ever the computer is not happy about is pin pointed and make necessary repairs, those function should begin to function normally.If not we can diagnose after the root problem has been rectified.

You are going to need wire schematics, service information on the coils, injectors, cam and crank position sensors, as well as fuel delivery and ignition data. With all this you should be able to pin point fault and make repairs.

And it may clear up just flushing engine oil. Short in town trips cause sludge, moisture build as engine cools overnight. If engine is not run long enough to burn off moisture, it attracts spent detergents in oil, and begins to create sludge. Sludge in VVT control valve will affect cam timing, can fool PCM to think ignition misfire.

If you do not have this equipment, befriend someone who does DIY and has these tools, as they should be more than willing to help. Or pay a shop diagnostic time, plus parts and labor for repair. Never confuse diagnostic time with labor, two different operations. But please, do not just start replacing parts, this can cloud the original fault. And I always charged customer for reinstall all original parts before attempting diagnosing the problem, so will any other shop. I’ve seen many replacements cause more problems.Some shops will refuse work if a bunch of parts have been replaced, and some will stick it to you seeing all the new parts. Just keep that in mind, going forward.

Hope this helps.

rey_winslow

Thanks! I'll see what is around me for help. Much appreciated!
My yearly maintenance is coming up, should I get the oil change before starting the diagnostics? I think I've got other fluids that need to be changed as well.

Rickman30

It wouldn't hurt to change oil. But if you normally drive as stated everyday. I'd recommend changing every 3k miles.

rey_winslow

Today's adventure took a bit of an unexpected turn. Drive to work no issues. Coming home I figured I'd let the car warm up first before leaving and doing a longer drive home. That plan fell apart right away. Turning the car on it started with rough idle, voltage was 14.7 but amps were 40+ and check engine light was on, I don't recall seeing that before. I let it run for a bit and then turned it off. Restarted and no rough idle but engine light was still on. It was running for a few minutes and then went into rough idle and current started to slide around, engine light is now flashing so I turned it off. Third time started fine but light was on but eventually moved to rough idle with amps all over the place, 50+ to -30 and engine light flashing again. Fourth time it started fine and ran fine all the way home though voltage was lower and amps were moving around. Scan gave me another code:

Now it's saying coil 4 has an issue, so maybe something to work with.
Thanks.