Help! Electrical Issue

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splinter-cell

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Hey guys,

I’ve been having a bit of trouble with the electrics in my Audi lately. On a long journey, the electrics will suddenly cut out. The engine will keep running but the instrument cluster, power steering, heaters, radio, windows etc stop working. AA fitted in a new battery and the issue still happened. My battery actually expanded which leads me to point to an overcharging alternator. Does anyone else have any other theories?



This is the video I took when I broke down.
 
Sounds like they didn’t remove the pressure relief plugs.

The cut-out can be difficult to diagnose. Sometimes a broken/loose earth strap (to the battery, under the battery box, under the car) will cause this.

Do you have access to VCDS to scan the car and see if there is any fault codes?
 
I don’t have access to VCDS at the moment. However, the AA did use their OBD reader on the car. Not sure if that helps.

Patrol found the following fault code/s:System : Engine control 1 - 7C3 / Diesel EDC Simos PCR 2P056300 - Power supply. Error Message : Signal too high.P214700 - Power supply, injection valves bank 1. Error Message : Short to ground.P15A100 - Neutral position sensor. Error Message : Signal improbable.
 
I had this similar issue on my previous VW POLO, it was the alternator overcharging, it was sending all sorts of error codes to the ECU, the very high voltage being produced caused these problems!


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splinter-cell said:
It literally expanded. Bulged up. The plastic on the side broke a little. Some acid leaked out. Had that rotten egg(sulphur) smell too.
Click to expand...

Battery is getting too hot, being overcharged causes this to happen


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samuelh_888 said:
Sounds like they didn’t remove the pressure relief plugs.

The cut-out can be difficult to diagnose. Sometimes a broken/loose earth strap (to the battery, under the battery box, under the car) will cause this.

Do you have access to VCDS to scan the car and see if there is any fault codes?
Click to expand...

It’s being overcharged, causes the plates in the battery to expand


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Pressure relief plugs in a battery?!? Never been heard of


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Abi said:
Pressure relief plugs in a battery?!? Never been heard of


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Click to expand...

Pressure relief plugs in batteries - kept in while transporting. The likes of the RAC and the AA often forget to remove them.
 
Abi said:
I had this similar issue on my previous VW POLO, it was the alternator overcharging, it was sending all sorts of error codes to the ECU, the very high voltage being produced caused these problems!


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Click to expand...

Abi said:
Battery is getting too hot, being overcharged causes this to happen


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Click to expand...

This is what I was thinking. However, it’s a bit of a mess because it’s not constantly reproducible. Side law I guess, whenever I’ve broken down, it’s always fixed itself by the time AA get to me and when they run their tests with the multimeter, everything seems fine. Really annoying.
 
splinter-cell said:
This is what I was thinking. However, it’s a bit of a mess because it’s not constantly reproducible. Side law I guess, whenever I’ve broken down, it’s always fixed itself by the time AA get to me and when they run their tests with the multimeter, everything seems fine. Really annoying.
Click to expand...

Yep my polo was intermittent, was only by chance when I happened to check the voltage and showed 17 + volts.
Back then I made a test rig out of a cheap digital volt meter and a cigar lighter plug. Monitored the voltage while driving.
With your symptoms, fried battery and egg smell (boiling battery acid) I’d put money on the alternator.


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Abi said:
Yep my polo was intermittent, was only by chance when I happened to check the voltage and showed 17 + volts.
Back then I made a test rig out of a cheap digital volt meter and a cigar lighter plug. Monitored the voltage while driving.
With your symptoms, fried battery and egg smell (boiling battery acid) I’d put money on the alternator.


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Ok great. Thanks for the help guys. Hopefully it’s just a case of replacing the alternator and nothing more. Appreciate the help.
 
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splinter-cell said:
Ok great. Thanks for the help guys. Hopefully it’s just a case of replacing the alternator and nothing more. Appreciate the help.
Click to expand...

Keep us informed on how you get on.


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Abi said:
Keep us informed on how you get on.


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Click to expand...

Just thought I’d give you guys an update. I’ve now had the alternator and battery replaced with brand new parts and everything seems fine for now. The guys who replaced the alternator mentioned that there is a bit of a voltage/amp decrease. My car originally had a 140A alternator installed. Could they have possibly installed a 110A alternator by mistake?
 
splinter-cell said:
Just thought I’d give you guys an update. I’ve now had the alternator and battery replaced with brand new parts and everything seems fine for now. The guys who replaced the alternator mentioned that there is a bit of a voltage/amp decrease. My car originally had a 140A alternator installed. Could they have possibly installed a 110A alternator by mistake?
Click to expand...

Why did they not fit a like for like unit? I’m still convinced that your original problem will now be cured though


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Abi said:
Why did they not fit a like for like unit? I’m still convinced that your original problem will now be cured though


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They said they fitted like for like but I can’t see what else would be causing an amp decrease. Unless maybe my permanent live dash cam was running when they did their test and didn’t realise.
 
splinter-cell said:
They said they fitted like for like but I can’t see what else would be causing an amp decrease. Unless maybe my permanent live dash cam was running when they did their test and didn’t realise.
Click to expand...

Just so I understand, what are the new output figures being compared too? Hopefully not the figures of the old alternator, as those would be incorrect as it was overcharging.
Normal battery voltage with the engine running could be anywhere between 12.5 and 14.5v depending on engine speed, amps depends on the equipment being used (blowers, rear window heater, headlights) etc
Hope this helps


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Abi said:
Just so I understand, what are the new output figures being compared too? Hopefully not the figures of the old alternator, as those would be incorrect as it was overcharging.
Normal battery voltage with the engine running could be anywhere between 12.5 and 14.5v depending on engine speed, amps depends on the equipment being used (blowers, rear window heater, headlights) etc
Hope this helps


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Click to expand...

I think they’re comparing to factory expected values. As far as I can see the voltage doesn’t seem to be an issue. They’re more concerned about a current drain of 0.127A. Like you said, it’s probably down to some equipment being left on.
 
splinter-cell said:
Hey guys,

I’ve been having a bit of trouble with the electrics in my Audi lately. On a long journey, the electrics will suddenly cut out. The engine will keep running but the instrument cluster, power steering, heaters, radio, windows etc stop working. AA fitted in a new battery and the issue still happened. My battery actually expanded which leads me to point to an overcharging alternator. Does anyone else have any other theories?



This is the video I took when I broke down.
Click to expand...

I came across this post whilst doing some searching for a similar issue with my A6 (C6). Last night the lights went dim at about 60mph (I was travelling with lights, heater, heated seats, radio and cruise control on), they stayed dim for about 5 seconds, before briefly returning then going out completely. I lost the lights, dashboard, radio, heater - the whole lot. The car also lost power too. Then I got an overcharging error followed by ABS, EPB and ESP warnings, before the lights returned and the errors cleared. It all took less than 20-30 seconds.

That's the second time it's happened in the last week, so to me it points to a faulty voltage regulator - assuming the loss of lights etc was a drop in voltage, then a sudden spike?

Wondered what your thoughts were.
 
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