[2000rpm]

Hi Guys,

I am facing some wierd issue with my Polo 1.6. I have observed the following symptoms in the last two months, which are making me think twice to take the car out for long drives.

• Clock is not up-to-date, even when I correct the clock while leaving my car and start my car after 2-3 days, the clock is incorrect.
• The Cranks sometime just fail, showed this to multiple battery guys, they said the battery is fine. The next attempt after the failed crank, starts the car perfectly.
• Yesterday, while driving, My instrument cluster went crazy, with the tacko and speedo doing random sweeps in spite of the car being at constant speed. A lot of lights in the dashboard flashed and this went away after some time. This happened a few times, and every time this happened, the clock reset to 0:00.
• If my music system is off and the car is on, the system button back lights blink for a fraction of second before switching off again.

Any possible diagnosis? Anyone faced this in any car before?

[abhishek46]

I think you should get your wiring loom/harness thoroughly checked.
These kind of random issues can result if there are issues with the wiring, especially if there is rat damage.

[sameerpatel90]

With respect to your concern there are a few things that needs to be cleared.

1. Are there any aftermarket electrical accessories fitted to the vehicle.
2. Age of the vehicle.
3. Check for any rat smell/impressions of rat entry.
4. As far as my experience there can be three possible issues,
a. The instrument cluster may be faulty.
b. Wiring damage between BCM (body control module) and instrument cluster. Basically the wire might have got a cut and causing short to ground.
c. The BCM itself may be faulty and an error with diagnostic tool can verify the same.

I hope you have visited the authorized dealership if not, please do the needful and update us their examination and inputs.

Waiting for your update at the earliest.

[sibot]

I know you've ruled out the battery being a culprit, but how old is the battery?

[Comrade]

I faced same exact symptoms long time back. After lot of troubleshooting, figured out that loose contact at the battery terminal was causing this. The battery terminal was size smaller (probably few mm clearnace) than the clamp. I got a copper cap to fill the gap, and it solved the problems.

Please check if there is any loose contact anywhere in the wiring harness.

[Jeroen]

Going by your symptoms I would suspect battery, battery terminals, main power distribution, grounding, wire harness. In that order too. Also happens to be the order from easiest to check to more complex.

Battery: when in doubt always check your battery. At least with a multimeter, preferably get it properly tested for load. Check voltage on the battery terminal with engine switched off and engine running.

Check the battery terminals. Not just visually, but take them off. If any were loose you will notice, but you need to take them off, and see if there is any corrosion. Clean and reconnect.

Next you want to make sure your power distribution is in good order. Any connection could be corroded and that will give a dip in Voltage. Some cars are equipped with main fuses, you will need to consult a workshop manual to find them most likely. They need to be taken out and checked/cleaned for corrosion.

Next figure out a few spots where you are expecting to see normal battery voltage. E.g. main lights and preferably near or at the ECU. Check the voltage with the engine switched off and running. You should get very similar reading to what you had before measuring directly at the battery terminals. More than 0,1-0,2V drop is suspect.

There will be a number of ground straps all around the car and engine. Try and find the main one. E.g. the engine and strap in and around the engine compartment and ECU. Again, you need to take them apart, clean and re-install.

One of my cars is very susceptible too voltage fluctuations due to corrosion. I have to go through all this cleaning of all contacts, grounds every few years!

Lastly the wiring harness. Simplest is to start with all visible connectors. Slide them off, check for corrosion, clean (usually just a blast with electro cleaner will do) and re install. You want to start with all the connectors on the engine first. So the MAF, throttle body, various sensors etc. If you can get at the ECU or other electronics same thing.

Whilst you are doing so keep a close look at visible signs for wire chaffing and check every connector that it fits properly, all pins are straight, wires are properly attached. Just give each wire a little pull. If you have followed my thread on fiddling with cars you will seen me do this several times on all my cars. And I found several problems with wiring, connectors and so.

Before starting disconnecting connectors or ground straps make sure to disconnect the battery mass cable first. Safety first!

You might also want to run an OBD scanner. It might give some indication. With symptoms like this don’t start swapping parts unless you absolutely sure everything else is working correctly. But the OBD error code might give an indication as to which parts are not working properly and that is most likely to not getting the correct voltage. So concentrate on the wiring, connectors of those first.

Trouble shooting these things isn’t particularly difficult, but it can be very time consuming.

Good luck
Jeroen

[AMG Power]

As mentioned, it’s the standard symptoms of a weak battery. Also check the terminals for a loose connection / corrosion.

If you can, fix another good battery and see if the symptoms appear. Don’t rely on the ASS’s assessment of the battery which may not have been done properly.

[srini1785]

Originally Posted by 2000rpm

[*]Yesterday, while driving, My instrument cluster went crazy, with the tacko and speedo doing random sweeps in spite of the car being at constant speed. A lot of lights in the dashboard flashed and this went away after some time. This happened a few times, and every time this happened, the clock reset to 0:00.

While battery remains prime suspect. When a IC makes such random sweeps, its behaving the way its programmed to do while car is starting. This is turn would make you want to look at the ignition switch.

PS: I have no knowledge of Polo electricals. So better check with your ASC.

[2000rpm]

Originally Posted by srini1785

While battery remains prime suspect. When a IC makes such random sweeps, its behaving the way its programmed to do while car is starting. This is turn would make you want to look at the ignition switch.

PS: I have no knowledge of Polo electricals. So better check with your ASC.

The polo dials dont make a sweep when you start the car. This can be ruled out!

[NevGin]

Nothing left to be said here as Jeroen has listed everything. Just to also let you know that at one point out of no where I had the same issue on a 1.6 TDI. Dashboard lit up, dials went crazy and the car just went limp. The wiring harness was changed as mouse bites were found on multiple parts of the loom. And to add to that, the car had returned from service just a day back. I suspect it happened on their watch and not where I used to park.

[2000rpm]

Originally Posted by Jeroen

Going by your symptoms I would suspect battery, battery terminals, main power distribution, grounding, wire harness. In that order too. Also happens to be the order from easiest to check to more complex.

Trouble shooting these things isn’t particularly difficult, but it can be very time consuming.

Good luck
Jeroen

Thanks a lot for the detailed inputs sir. I tried to check the wiring in places visible and found no specific cuts. The battery terminals are tight, they were loose but the service center had added some copper wires for tightening the clamps, they are pretty tight!

I have an additional observation and a the behaviour on video.

Additional Observation - This blinking of lights is accompanied by a clicking sound (can be heard in Video 2 very clearly). I am putting up both videos - the latest one and one when the problem was very minor (3 months back) for comparison. I think the two points may give a better indication for the diagnosis.

Latest Video of Christmas light and random sweep behaviour

https://youtu.be/VlgpVzdtF2E

Video a few months earlier, when the car only gave sporadic failed starts.

https://youtu.be/7VzzYCxMcMk

[Jeroen]

Originally Posted by 2000rpm

Thanks a lot for the detailed inputs sir. I tried to check the wiring in places visible and found no specific cuts. The battery terminals are tight, they were loose but the service center had added some copper wires for tightening the clamps, they are pretty tight!
l]

Really, copper wires to get the battery terminals tight?

Sorry, but a battery terminal should not need anything extra. It should fit properly and it should be able to tighten properly without the use of additional wires or anything. This almost sounds as if they were a size to big?

Could you share am image of these battery terminals?
Thanks

Jeroen

[hellmet]

I just dealt with something a little similar on our M800 today. It runs perfectly fine otherwise, but for the last couple of days it was acting weird with lights. The high-beam dash-light would turn on, sometimes all the time, sometimes when the brake lever is depressed. The roof light wouldn't turn on, or would toggle the high-beam light on and off.

The pilot lamps also stopped working.

There was some hesitation with car cranking as well.

After spending an hour insulating some wires, tugging on battery terminals, and trying what not, I tried wiggling the blinker-module, and lo and behold, everything started working. Curious, I took out the module, and the behaviour could be replicated when the fuse box was wiggled.

So, I opened up the fuse box, and pressed onto all fuses one by one.

I have a working car now. I love this car.

Give it a shot, maybe!

[srini1785]

Originally Posted by 2000rpm

Additional Observation - This blinking of lights is accompanied by a clicking sound (can be heard in Video 2 very clearly). I am putting up both videos - the latest one and one when the problem was very minor (3 months back) for comparison. I think the two points may give a better indication for the diagnosis.

The click sounds like an onboard relay going on/off. Probably a power relay problem and could explain the ON/OFF of the IC. Such faults need to be checked at ASC. From what I know IC boards are repairable to some extant.

Again : I have no knowledge of Polo electricals. So better check with your ASC.

[2000rpm]

Originally Posted by Jeroen

Really, copper wires to get the battery terminals tight?

Sorry, but a battery terminal should not need anything extra. It should fit properly and it should be able to tighten properly without the use of additional wires or anything. This almost sounds as if they were a size to big?

Could you share am image of these battery terminals?
Thanks

Jeroen

Sure sir, plan to do a few more self tests in the evening.

Just consolidating all the symptoms in one post here

Clock is not up-to-date, even when I correct the clock while leaving my car and start my car after 2-3 days, the clock is incorrect.
The Cranks sometime just fail, showed this to multiple battery guys, they said the battery is fine. The next attempt after the failed crank, starts the car perfectly.
Yesterday, while driving, My instrument cluster went crazy, with the tacko and speedo doing random sweeps in spite of the car being at constant speed. A lot of lights in the dashboard flashed and this went away after some time. This happened a few times, and every time this happened, the clock reset to 0:00.
If my music system is off and the car is on, the system button back lights blink for a fraction of second before switching off again.

Additional Observation 11th March - This blinking of lights is accompanied by a clicking sound (can be heard in Video 2 very clearly). I am putting up both videos - the latest one and one when the problem was very minor (3 months back) for comparison. I think the two points may give a better indication for the diagnosis.

Additional Observation 12th March - The car refused to start yesterday. The crank was resulting in two to three gallops like noise post which the galloping would also stop. While the car refused to start, the power windows and music system were working just fine!