Battery Drain While Driving/ABS/Airbags/Electrical

[JBjunior]

So, 2003 Jetta with a brand new alternator and multiple batteries with the same results. Drove it 300+ miles today and it drained two batteries even though the alternator appears to be working properly.

ABS light and Air Bag light came on a couple of times intermittently. Ran it on VCDS and this is what I got. I am suspecting a ground/short, but hopefully there is something quick I can check.

Any help is greatly appreciated.

Codes I have are:

Engine

18057 - Powertrain Data Bus
P1649 - 35-00 - Missing Message from ABS Controller

ABS Brakes

01276 - ABS Hydraulic Pump (V64)
012 Electrical Fault in Circuit - Intermittent

00668 - Supply Voltage Terminal 30
008 - Implausible Signal - Intermittent

Airbags

00532 - Supply Voltage B+
07-10 - Signal too Low - Intermittent

Steering wheel

00926 - Terminal 30
07-10 - Signal too Low - Intermittent

Instruments

01316 - ABS Control Module
49-10 - No Communications - Intermittent

CAN Gateway

01316 - ABS Control Module
49-10 - No Communications - Intermittent

Central Conv.

00931 - Locking Module for Central Locking; Rear Right (F223)
54-10 - Incorrectly Equipped - Intermittent

01359 - Internal Central Locking Switch; Passenger Side (E198)
27-10 Implausible Signal - Intermittent

Radio

00668 - Supply Voltage Terminal 30
07-10 Signal too Low - Intermittent

00856 - Radio Antenna
36-00 - Open Circuit

01305 - Databus for Infotainment
37-10 - Faulty - Intermittent

 

[AnotherPerson]

Some of this can happen with low voltage. With a charged battery and running what voltage do you see at the terminals? I've seen posts of people doing 300miles on a battery alone by trying to save energy. The car itself uses very little power. I would think it's glow plug related. Fans and the 2 glow plug systems are your largest power draws. Simple way to check if the glow plugs are pulling it is disconnect all 7 once you get warmed up and head out for a drive.


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[JBjunior]

Some of this can happen with low voltage. With a charged battery and running what voltage do you see at the terminals? I've seen posts of people doing 300miles on a battery alone by trying to save energy. The car itself uses very little power. I would think it's glow plug related. Fans and the 2 glow plug systems are your largest power draws. Simple way to check if the glow plugs are pulling it is disconnect all 7 once you get warmed up and head out for a drive.


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Charged battery and running it is at 14.7 volts at the terminals.

Thanks for pointing that out about the codes. It looks like all the ones I am worried about are related to the low voltage. They are probably just symptoms and not causes.

 

[JBjunior]

Main glow plug harness is new and I inspected all wiring. Coolant glow plug harness cracked as usual, I removed it and moved it to the side. I inspected all other wiring and there are no noticable issues.

Brand new battery and alternator, but it is possible there is someting going on with the alternator. I have always thought if it is putting out 14+ volts it was good.

It drained a known good battery in a few hours last night so if the alternator is working 100% it is something with a significant draw to not only drain the battery but overcome the alternator recharging it. Thoughts?

 

[stamp11127]

If you have access to a meter with a dc amp clamp you can measure the current draw on the battery. Then start disconnecting the big draw circuits. If you don't have the clamp there is a post on the forum with a chart from vw listing current draw on each fuse type and rating when performing voltage drop testing.
The redneck method would be to charge the battery and disconnect a circuit. Measure battery voltage 2 hours later. If there is a big drop then the circuit you disconnected wasn't it.
If you disconnect live circuits, any that has a big draw will spark noticeably and may make a crackle sound. You'll know it when you get it.
I would look at the coolant glow plug relay and alternator before anything else.

 

[Vince Waldon]

the alternator appears to be working properly.

This is where I'd start... what does "appears" mean?

For all practical puposes the battery's sole job is to start the car. After that, it's all about the alternator, and so if your battery(s) are being discharged while driving there's a problem with the alternator or associated system, period. A properly-working alternator is more than capable of keeping up with whatever electrical loads the car throws at it, once the engine is running.

Also worth noting that the alternator system is *not* well monitored by the ECU for faults, so there won't be much info from a scan. And unfortunately the ALT idiot light is well-named, as it can be an idiot and not come on when it should.

Your best bet is a multimeter hooked up to the battery terminals:

- should read around 12.5V with the engine off
- should jump to at least 13.5V when you start the engine

No voltage jump? You've confirmed a problem with the alternator system, and can dig in deeper, starting with measuring the voltage on the output stud of the alternator and a check of the alternator fuse itself.

 

[JBjunior]

This is where I'd start... what does "appears" mean?

For all practical puposes the battery's sole job is to start the car. After that, it's all about the alternator, and so if your battery(s) are being discharged while driving there's a problem with the alternator or associated system, period. A properly-working alternator is more than capable of keeping up with whatever electrical loads the car throws at it, once the engine is running.

Also worth noting that the alternator system is *not* well monitored by the ECU for faults, so there won't be much info from a scan. And unfortunately the ALT idiot light is well-named, as it can be an idiot and not come on when it should.

Your best bet is a multimeter hooked up to the battery terminals:

- should read around 12.5V with the engine off
- should jump to at least 13.5V when you start the engine

No voltage jump? You've confirmed a problem with the alternator system, and can dig in deeper, starting with measuring the voltage on the output stud of the alternator and a check of the alternator fuse itself.

Thanks for the response! As noted above, it jumps to over 14 volts with the car running. So that is why it appears to be working. My comment meant, even if I am getting 14+ volts, is it possible the alternator isn't working properly in some other capacity?

 

[UhOh]

Is it only draining when running, not if left parked (and not running)?

Isn't 14.7 volts outside of normal charging rates? If so, then perhaps the regulator is bad?: high voltages can also cause problems.

 

[stamp11127]

Most literature will state 13.5-14.5 volts as being the normal range. I've seen slightly higher, 14.8 without issues and start cooking things. I tell the students that once you hit 15 volts then there may be issues. The electronics in today's vehicles can handle slight over voltage. I watched a guy fry an ecm with an unregulated Start All that put out at least 16 volts, probably was in the 20's though.

 

[JBjunior]

Is it only draining when running, not if left parked (and not running)?

Isn't 14.7 volts outside of normal charging rates? If so, then perhaps the regulator is bad?: high voltages can also cause problems.

With everything I know right now, it is only while running/driving, not while parked.

 

[wonneber]

With everything I know right now, it is only while running/driving, not while parked.

If running with the headlights on, fan at full, and seat heaters on you should still see 14 or more volts.
If its at least that the battery is getting charged.
If the battery is bad no amount of charging will make it good.
With the car running try measuring AC voltage at the battery.
I would not want to see much.

Rich W.

 

[Vince Waldon]

Thanks for the response! As noted above, it jumps to over 14 volts with the car running. So that is why it appears to be working. My comment meant, even if I am getting 14+ volts, is it possible the alternator isn't working properly in some other capacity?

Whoops... didn't see the post with the reading in it.

Yeah, 14.7V is a tad high... but probably within the tolerance of a multimeter.

This is indeed a strange problem, since that is more than enough voltage to charge the battery, and it would not be supplying that nice high voltage if it also wasn't supplying enough current to run everything in the car as well.

Perhaps back up a bit: when did the problem start, how did the car come to have a new alternator and two new batteries, what kinds are they and where did they come from, etc.

There's a missing piece to this story perhaps... and perhaps there's a clue in there somewhere?

 

[JBjunior]

If running with the headlights on, fan at full, and seat heaters on you should still see 14 or more volts.
If its at least that the battery is getting charged.
If the battery is bad no amount of charging will make it good.
With the car running try measuring AC voltage at the battery.
I would not want to see much.
Rich W.

I will measure tomorrow.

 

[JBjunior]

Whoops... didn't see the post with the reading in it.
Yeah, 14.7V is a tad high... but probably within the tolerance of a multimeter.
This is indeed a strange problem, since that is more than enough voltage to charge the battery, and it would not be supplying that nice high voltage if it also wasn't supplying enough current to run everything in the car as well.
Perhaps back up a bit: when did the problem start, how did the car come to have a new alternator and two new batteries, what kinds are they and where did they come from, etc.
There's a missing piece to this story perhaps... and perhaps there's a clue in there somewhere?

I just bought the car. In the last few months (I have the receipts) the guy drove the car and came out to use it later and it wouldn't start. Got it jumped and went and bought an alternator. Didn't fix the problem and bought a battery. I brought a known good battery with me when I bought the car. About half way through the journey, first battery was dead. Put in the known good battery and continued on the journey. Got it home and started having the low voltage problems about 10 minutes from the house. Battery was dead when I checked.

Which brings me back to the "appears to be working" for the alternator. Is it possible it is charging the battery but isn't supplying the rest of the car? Otherwise, why is the low voltage issues (and drained battery) happening once the battery is sulfated?

 

[Vince Waldon]

Which brings me back to the "appears to be working" for the alternator. Is it possible it is charging the battery but isn't supplying the rest of the car?

Nope... that's what's strange. I don't see how it's possible for you to measure 14.7 V at the battery and yet the battery is not being kept charged.

All wires and grounds being in place the system voltage is the system voltage... that same 14.7 V is present everywhere in the car... at the battery, at the alternator, and at all the loads.

If the alternator was weak or struggling somehow you'd not have a system voltage of 14.7V... there's no way for the alternator to send more voltage to different parts of the car than others.

Hmmmmmm.

OK, the usual culprit when very strange electrical things happen... and weird readings/symptoms are taking place... is the grounds. A bad ground can lead to all kinds of "interesting" behaviour that seems impossible in the normal laws of physics.

So: in lieu of a better suggestion at the moment, I'm gonna suggest having a very close look at all the ground cables. There should be a very heavy duty ground cable between the battery and the top transmission bolt, and also several very important ground connections at two ground posts *under* the battery box (battery and battery box gotta come off to get to 'em) that like to corrode over time.

Even if they look fine it's worth unbolting them and cleaning everything with sandpaper. The grounds under the battery box in particular can look fine but be corroded within.

Not sure it will fix anything... but good to eliminate as a suspect *and* the symptoms you're describing still don't fit a straightforward pattern... at least to me.

 

[JBjunior]

Nope... that's what's strange. I don't see how it's possible for you to measure 14.7 V at the battery and yet the battery is not being kept charged.

All wires and grounds being in place the system voltage is the system voltage... that same 14.7 V is present everywhere in the car... at the battery, at the alternator, and at all the loads.

If the alternator was weak or struggling somehow you'd not have a system voltage of 14.7V... there's no way for the alternator to send more voltage to different parts of the car than others.

Hmmmmmm.

OK, the usual culprit when very strange electrical things happen... and weird readings/symptoms are taking place... is the grounds. A bad ground can lead to all kinds of "interesting" behaviour that seems impossible in the normal laws of physics.

So: in lieu of a better suggestion at the moment, I'm gonna suggest having a very close look at all the ground cables. There should be a very heavy duty ground cable between the battery and the top transmission bolt, and also several very important ground connections at two ground posts *under* the battery box (battery and battery box gotta come off to get to 'em) that like to corrode over time.

Even if they look fine it's worth unbolting them and cleaning everything with sandpaper. The grounds under the battery box in particular can look fine but be corroded within.

Not sure it will fix anything... but good to eliminate as a suspect *and* the symptoms you're describing still don't fit a straightforward pattern... at least to me.

I will do the ones under the battery box in the morning. I removed the battery box and looked at them today and they looked fine and I still have it disassembled so it will be easy. Where is the one on the transmission? Where are the other grounds in the engine bay that might be relevant?

 

[wonneber]

I should have thought of this sooner.
With the car running do a voltage drop test from the following:
From the battery + post (not clamp) to the alternator + stud.
From the battery - post to the alternator case.
I would not want to see more then a few tenths of a volt.
More then that start tracing the wire from the battery to where the loss is lost.

Rich W.

 

[Vince Waldon]

Yup, at the least a good idea to verify exactly where the 14.7V is being measured... because, to your point, there can be a difference between "at the clamps" and "with the probes poking into the actual battery terminals themselves".

OP: the best way to find the big ground on the transmission is to follow the negative battery terminal cable. It will probably be fine, since the car starts OK, but this is a weird problem, so something that should be OK must not be OK.

 

[JBjunior]

Hmmm, so my previous comment about having 14.7 at the battery is null and void. I am getting 12 volts at the battery with a 2.5 volt differential at the alternator. The alternator is putting out 14.5 but something is stopping it from getting to the battery/system.

 

[Vince Waldon]

Hmmm, so my previous comment about having 14.7 at the battery is null and void. I am getting 12 volts at the battery with a 2.5 volt differential at the alternator. The alternator is putting out 14.5 but something is stopping it from getting to the battery/system.

Wel, this is *very* important new information.

The good news is that you'll be able to track this down pretty quickly, 'cause it's a very short path between the alternator.

After attaching the negative terminal of your multimeter to a good ground work your way along the path with your positive terminal:

- the output stud of the alternator (that's where you're getting 14.7 volts, right?)
- the end of the alternator wire at the fuse block on top of the battery box
- the other end of the alternator fuse
- the positive battery cable clamp at the battery
- the battery post itself (this is where you're reading the 12V, right?)

That's all there is to the path.

 

[JBjunior]

Wel, this is *very* important new information.
The good news is that you'll be able to track this down pretty quickly, 'cause it's a very short path between the alternator.
After attaching the negative terminal of your multimeter to a good ground work your way along the path with your positive terminal:
- the output stud of the alternator (that's where you're getting 14.7 volts, right?)
- the end of the alternator wire at the fuse block on top of the battery box
- the other end of the alternator fuse
- the positive battery cable clamp at the battery
- the battery post itself (this is where you're reading the 12V, right?)
That's all there is to the path.

Thanks Vince and everyone else for your help. You are right, it was a very quick discovery. I thought maybe there was something else in between the alternator and the fuse. There obviously isn't so I measured the wire terminal next to the alternator stud and wasn't getting the 14 volts I was looking for. I removed the wire from the alternator, tested the wire (good), and then assumed that the connection to the alternator had to have an issue. I re-installed it correctly and tightly..... and..... GOOD TO GO. Thanks for all of the help!

 

[Mongler98]

any one can help me .... plz my skoda 1.4 tdi strage intermittent problem abs, parquing brake light , then steering wheel light and power steering loss.. voltage drop at a level tht engine missfire instrument cluster go off. but after shutting down engine start again all ok. ive checked all fuses nothing blown... local mechanic after diagnose suggest me change battery .. but even after battery change problem keep coming. i am sharing a link to see the problem..

You need to start your own thread

 

[imrasl]

thnks already done.