ECU's and Electronics

[Vettech]

Definitely not Corvette related, however, this concerns ECU in Fords.

Had an ˋ03  BA Fairmont since ˋ06, only complaint is that it eats headlight bulbs like lollies.
Recently car cuts out and engine stops, this occurs stopped at idle, reversing in the carpark or at 110 down the highway.
Alt is located under a coolant hose and the Power steering pump/switch and hoses etc.
All of these have leaked thru the Alt, plus grease, oil, road grime etc etc. The charge voltage goes from 14.5 up and up, car cuts out at ˜23Volts.
Problem has become VERY bad, suspected the Alt - so I fitted a new one, everything looked ok. The old Alt internals were something to behold.
Put a meter on battery but alas, somethig is driving the Alt output up and up, car cuts out.

This scenerio may now explain why the light bulbs are blowing. In the past I have measured the volts across the battery, 14,5 is a bit high, but not excessive.
I have done this may times and never seen this sudden voltage rise - I hate intermittent faults.

QUESTION.  Anyone had a issue like this?
Is  it safe to assume its the ECM?
Anyone heard of the cause being Electrolitic Caps in the ECM being at fault?

Iˋm at the point where I pull the ECM apart, or take it to Ford or similar to fix it - by the way Ford Tech Dept could not give me even a clue, but want to charge $100 per hour to see if they can locate the fault..

Any ideas  or info would be greatly appreciated. Tks.

[stingray]

Hi Doug, the $100/hour is good for the apprentice to learn on, try a same model ford blog and see what info you may get from owners, good luck

[bfit]

Ford ECU now that could be contradiction in terminology for the uninformed.
Ford  ECU =Error Correction Unit
Buy a Chev , all sorted
Bfit

[bfit]

Definitely not Corvette related, however, this concerns ECU in Fords.

Had an ˋ03  BA Fairmont since ˋ06, only complaint is that it eats headlight bulbs like lollies.
Recently car cuts out and engine stops, this occurs stopped at idle, reversing in the carpark or at 110 down the highway.
Alt is located under a coolant hose and the Power steering pump/switch and hoses etc.
All of these have leaked thru the Alt, plus grease, oil, road grime etc etc. The charge voltage goes from 14.5 up and up, car cuts out at ˜23Volts.
Problem has become VERY bad, suspected the Alt - so I fitted a new one, everything looked ok. The old Alt internals were something to behold.
Put a meter on battery but alas, somethig is driving the Alt output up and up, car cuts out.

This scenerio may now explain why the light bulbs are blowing. In the past I have measured the volts across the battery, 14,5 is a bit high, but not excessive.
I have done this may times and never seen this sudden voltage rise - I hate intermittent faults.

QUESTION.  Anyone had a issue like this?
Is  it safe to assume its the ECM?
Anyone heard of the cause being Electrolitic Caps in the ECM being at fault?

Iˋm at the point where I pull the ECM apart, or take it to Ford or similar to fix it - by the way Ford Tech Dept could not give me even a clue, but want to charge $100 per hour to see if they can locate the fault..

Any ideas  or info would be greatly appreciated. Tks.

You know and uncontrolled alternator can do a 100V, that will fry most boards.

[Vettech]

Thanks Alan, yes I've tried lots, rang experts, including Ford and other private companies specialising in ECU repair.
I  get conflicting statements, BUT none can emphatically confirm that the ECU controlls the Alt output.

I found my Autel AL519 Can/OBDII decoder, and put it on the car, says no Codes, did all sorts of checks - nothing, but I have an Airbag/restraints light lit on the dash, and I know its in the yellow connector under the drivers seat, Soool!?!....

Bates the following questions.
1. Why does the ECU not know of the seat belt light.
2. Does the ECU  actually controll the Alt output.
3. The two wires (smaller) to the Alt - what do they actually do!?!?.

Ahhhhhhhh!.... tomorrow I think I'll be looking for a circuit diagram,  maybe a call to Bosch or the like.

Pity we dont have an Auto Electrician in the club??...........

[Scott]

Unfortunately the ford forums are ghost towns these days since bookface killed most of them. 
But there is still info in them.  You just have to search through.  You'll most likely have to join up to a few to search properly.  I know I did. (03 BA XR6T owner here)
The turbo forums will probably have more info, as they are more enthusiast based, rather than P platers talking about rimz.

The info on the face book groups can be very hit and miss.  Lots of people who know nothing giving suggestions with no back-up knowledge.

[bfit]

Post here
See what input you get

https://www.corvetteforum.com/forums/c4-tech-performance-48/

[Vettech]

Thanks Guys, been thru the ropa dope today with Ford HQ who only have a girl, who fobs you off to your local dealership, who answers, records your question and then dont come back, and they will not let a mechanic or tech  talk directly to you.

The Private "ECU Repairer" cant answer the simplest questions. Change attach, search Mitsubishi Alt and not ECU.

Surfed today and found that the BA has a simple Alt not a smart one like the next Ford model, these use PWM (pulse width modulation) at about 128hz from the ECU to adjust current output (controls the field winding), but either way the volts range should ONLY vary from 13.8 ~ 14.4Vdc.

OK - so the ECU doesnt get involved with the Alt, good thing I didnt pull the ecu apart, esp since it looks to be "epoxy or tar/ silastic filled", I suppose I better bolt her back in place, I only ground the "security rivets" off at the top.

But interestingly, it appears that high output can be a symptum of faulty wires - the two thin ones in the plug or even Earths, since the Alt frame is its earth and of course it is bolted directly to the block, but there should be wires to earth the block to frame to chassis and battery......

Now I degreased then washed with solvent the 2x wire plug but it was a bit dodgey, hope tomorrow is fine, time for more checks.

Now for roast chicken dinner.....

[bfit]

I have a multimeter screwdriver and a 2lb hammer send it over and I’ll look at it for you.
Bfit
Seriously it’s an alternator not a iPhone it’s only a generator with a rectifier . What do you want it to do.

[Vettech]

All new style Alternators are.

1. Three (3) phase AC voltage alternators
2. Utilise three phase full wave rectification.
3. Normally self excited via a second set of smaller diodes.
4. On board constant voltage controll circuit.(13.8~14.4)

Three phase supplies greater current output in a smaller package.
By controlling the field windings the current can be adjusted from a couple of amps up to the rated output (ie; 110Amps)
The three phase full wave gives a smoother, flatter DC output, less ripple means less noise in audio etc ccts.

Regards.

And generators are DC output

[bfit]

So what is it’s problem

[MY081]

I love it when you guys talk like this !!!!

[bfit]

The alternator in this one works
http://www.graysonline.com/lot/0001-3431084/motor-vehiclesmotor-cycles/2015-chevrolet-corvette-z06-my16-6-2l-supercharged-lt4-v8?redirect=0

[bfit]

?

[Vettech]

Its sold.

Removed +ve cable assembly. Wires and cables in wrappings and corrugated tube.

Still full of all manner of fuel, P/S fluid, coolant, dirt, sand.......

Sensing wires giving all manner of varying resistance.
Dissmantled the plug, cleaned, soldered the crimp, retensioned etc

Appears the Alt sees 12v on this lead, if low it upps the Alt output.
If this lead has resistance, then the voltage becomes low.

Re-assembled the plug/cable and replaced, appears fault lifted, but then again this was an "intermittent" fault to stsrt with........

[bfit]

Have you changed the battery in the multimeter
Bfit

[Vettech]

Volt and ammetres do not require batteries.

But this here Ipad does - good night.

[bfit]

Arr and then there is ohms , resistance ,
To battery or not to battery that’s is the question
Bfit

[Vettech]

This car was fine for many years, but then started to eat H4 headlight globes, some one said the Alt output is set tooo high. Was fine each time I checked.
If going over 80kph I would always put headlighrs on - new cars call this "daytime running lights", so blowing globes Would be inevitable.

But if Alt and wiring was defective, causing short stints of over voltage, then no wonder the globes went.

But this would eventually cause kaos with the electronics.

I've now replaced both Batt, wiring and Alt.
Voltage is 13.8 - 14.4, does not miss a beat, irrespective of loads. (A/C Highbeam etc)

We also have a Jaycar $14 el cheapo digital display voltmetre taped to the dash and reading volts at Cigar lighter. In field of vision, easy to read.

Car now cuts out more than ever, but Alt output is constant, we are now down to the last faults, most likely caused by long term high Alt outout.

Now it goes to Ford........... there is no choice, the ECM Iookes tobe epoxy filled, changing electrolytics or capacitors is out of the question.