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VAG Smart charge alternator - Fixed #

Posted by Rob Nicholson on November 18, 2012, 11:30 pm

Year of Manufacture *: 2006

I have a Dodge Caliber in at the moment with the VAG 2.0TDi engine, it is having charge related issues FC;43 in engine (charge too low) and ESP;C2101 (charge too high) modules but is charging (amp clamp on alternator output to battery). It came to me after having an aftermarket alternator fitted from another garage (original battery so should be right spec silver type) it has the 2 wire connector at the alternator I have continuity on one wire to the engine ECU and a PWM waveform when running, the other wire reads battery voltage when running, I think this wire should have a PWM signal with the engine running? I would like to check continuity on this second wire but as I have no wiring diagram, is this wire also likely to be connected to the engine ECU or to the body control module? I do not want to change the alternator to find I have a broken wire!
Any help appreciated
Thanks
Rob

Re: VAG Smart charge alternator #

Posted by Tony Sefton <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT5581' width='330' height='300' border=0 style='border:none;'> on November 19, 2012, 7:50 pm, in reply to "VAG Smart charge alternator #"

If My Memory serves me right. The 2 Terminals on a VW Alternator are D+ which works just like a normal warning light wire which is usually about 2v with ignition on and goes to battery voltage with the engine running, I think that terminal is in the rounded end of the D shaped plug.

The other Terminal is DFM which is a monitoring signal and as you say goes back to the ecu.

Are you sure the Codes aren't there from the original Alternator. ? Or do they clear and return once its re-started. ?

What voltage is it charging at. ??

Fixed #

Posted by Rob Nicholson on November 19, 2012, 9:54 pm, in reply to "Re: VAG Smart charge alternator #"
Message modified by board administrator November 20, 2012, 3:20 pm

UKAT5581? I have posted sometimes and my membership # has displayed rather than my name dunno why this happens and there are no member numbers in the name database.

I had a charging voltage of 14.8 at the battery when running the batt had never been flat the KTS would clear engine & ABS faults but they would reappear with one saying too high and the other too low?

The D shaped 2 pin at the alternator with KOEO had 10.6 volts from the engine ECU wire and no volts at the other pin, when running the engine ECU wire scoped would show a PWM signal from 0v to 14.5 running but did not vary the on off time with load, the other wire was still 0v I decided this should have a voltage (from the BCM?) I thought the (cheap aftermarket!) alternator was ok because it was sending a PWM signal to the ECU but couldn't vary it as it had no input reference so out with rad fans etc pulled all loom out from front of the engine cut open and did indeed find the other wire broken phew!

Post repair the PWM signal to the engine ECU varied greatly with load and the fault codes cleared the other wire from BCM? with engine running had 14.5v I didn't check the voltage from this with different loads I guess this does alter but only slightly

Thanks for the reply

Rob

Members details

Posted by Peter Warman <iframe src='https://members4.boardhost.com/ukautotalk/info/user=Peter+Warman' width='330' height='300' border=0 style='border:none;'> on November 20, 2012, 8:06 am, in reply to "Re: VAG Smart charge alternator / FIX"
Peter Warman - Administrator

Hi Rob and All

The reason a post sometimes puts the members username (UKAT5***) in the "Your Full Name" field is because browsers that have "Auto Fill" activated will put your username in the "Your Full Name" field because it feels like it

This is a quirk with Auto Fill, it does not get it right all the time

Its up to the member to check that the fields are filled in correctly rather than just clicking "Post"

I do correct them eventually when time allows

If you look under the "Posted by" in the header, you will always see the members name even if their user name is displayed, this also allows me to see if the registered member is posting

HTH

Peter

Re: Members details

Posted by Rob Nic <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT5122' width='330' height='300' border=0 style='border:none;'> on November 20, 2012, 8:51 pm, in reply to "Members details"

Thank you Peter and Tony for the reply

Rob

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