How do I diagnose (and find) a faulty relay?

[Declan O'Shaughnessy]

Hi All,

 

I've had a problem with a strange "ticking" or "clicking" sound from behind the steering wheel ever since I bought the Superb in 2010. I posted on here about it at the time, but never really found a possible answer to what might be causing it.

 

Having put up with it for the last 7 years, I'm now trying to get to the bottom if it again. The problem is that it is intermittent and I've never been able to put my finger on why it happens. It might happen 30 seconds after sitting into the car. It might not happen for 2 hours after sitting into the car. It might only happen once per trip. It might happen every 5 minutes during a trip (where a trip might be 3 or 4 hours). The closest I've come to being able to predict when it might happen if after I turn the steering wheel to full lock (or almost). So after pulling out from a T-junction or something (though this isn't the only time it happens).

 

The closest I can get to describing the sound is that, if you remember the little "click" or "tick" that you hear when the heated rear windscreen turns off, imagine that constantly turning on and off in rapid succession. That's what it sounds like to me, and it sounds like it comes from behind or just under the steering wheel (though I know pinpointing where a sound is coming from in a car can be a fool's errand!).

 

What I'm thinking is that, because the sound sounds so similar to the heated rear windscreen turning off, that it is very likely to a faulty or malfunctioning relay. Given that it seems to regularly happen after turning the steering wheel, could it perhaps be a relay for the power steering (if such a thing even exists)? If it is likely to be a relay, how do I go about (a) finding and accessing the relays behind the wheel / dash and (b) how the hell would I then find and diagnose the troublesome relay? It never seems to happen when the car is motionless, so even if I could pull in to the side of the road when it happens and whip off the dash fascia or something, I think it's likely to stop before I can get close enough to find it.

 

Or, given that the same thing has been happening for 7 years and the car is still working perfectly, should I just put up with it and leave well alone? You can't hear it when the radio is on to be honest, and I'm loathe to pay an auto electrician good money to find something that might not be findable...

 

Any thoughts / advice / suggestions welcome. Have a great weekend everyone!

[jafo]

Isn't power steering electric on the Superb? Maybe something is wrong there ?

[chimaera]

If everything is working it's highly unlikely to be a failed relay. The main relay panel is deep down in the dashboard near the driver's right knee. It could be some part of the steering wheel assembly catching when you turn the wheel, possibly the clock spring.

[LightRain]

For your information.

From what I can tell, the relays under the steering wheel are:

Holder A:

1 - Terminal 15 voltage supply relay (ignition on, engine off supply)
2 - Heated rear window relay
3.1 - Dual tone horn relay
3.2 - Fuel pump relay
4 - Voltage supply relay, terminal 50 (ignition starting supply)
5 - X contact relief relay (ignition starting load reduction relay)

 

Holder B:

1 - Low heat output relay
- Fresh air blower relay
2.1 - Continued coolant circulation relay
- Additional heater fuel pump relay
2.2 - Auxiliary heater operation relay
3 - High heat output relay
4 - not assigned
5 - Headlight washer system relay

 

As you can see, most of these relays are pretty critical to everything working as expected, as chimaera says, it is unlikely to be a relay. However, if you want to make sure, you could test each relay individually. Alternatively, you could remove one (of the few non-critical ones) at a time and see if it makes a difference. Bear in mind, that's a lot of effort for something that may not be a relay. Do you have access to VCDS, maybe there's a code or 2 stored about some issue?

 

Also, jafo makes an interesting point, although you aren't noticing anything unusual in the steering itself also all the control hardware for that system is located near the rack. It is worth bearing in mind though.

 

What happens if you turn the wheel while stationary, does it happen then?

[Declan O'Shaughnessy]

Thanks for all the replies so far!

 

@LightRain I did a quick scan this morning and found a few faults logged, which I've listed below. No idea how to go about solving any of them though!

 

If I turn the wheel with the car stationary, I've never been able to make the ticking sound happen. It has, on occasion, happened as soon as I've set off (so still in the driveway and haven't actually turned the wheel at all to that point), though that has only happened once or twice.

 

Fault codes:

 

Address 09: Cent. Elect.       Labels: 1K0-937-08x-09.clb
Control Module Part Number: 1K0 937 087 A    HW: 1K0 937 087 A
  Component and/or Version: BCM PQ35  H+  020 0358
           Software Coding: 48990AB8D841F1C040080084110089A401711BAE632085605C4040000000
            Work Shop Code: WSC 33361 790 00000
                      VCID: 2F69178F7E06536
1 Fault Found

01134 - Alarm Horn (H12)
            004 - No Signal/Communication
             Freeze Frame
                    Fault Status: 01100100
                    Fault Priority: 4
                    Fault Frequency: 1
                    Reset counter: 73
                    Mileage: 224833 km
                    Time Indication: 0
                    Date: 2101.14.14
                    Time: 15:36:42

             Freeze Frame
                        Term 15 On
                    Voltage: 12.25 V
                        ON
                        ON
                        Term 50 Off
                        OFF
                        OFF

 

Sunday,15,October,2017,08:15:41:10074
VCDS Version: Release 11.11.0 (x64)

                Address 15: Airbags       Labels: 5N0-959-655.lbl
Control Module Part Number: 3T0 959 655     HW: 3T0 959 655
  Component and/or Version: J234__LAJ VW10 HI   1815
           Software Coding: 0016714
            Work Shop Code: WSC 33361 790 00000
                      VCID: FEF77ACBA9ECEAE
1 Fault Found

00532 - Supply Voltage B+
            002 - Lower Limit Exceeded - Intermittent
             Freeze Frame
                    Fault Status: 00100010
                    Fault Priority: 3
                    Fault Frequency: 3
                    Reset counter: 171
                    Mileage: 165094 km
                    Time Indication: 0
                    Date: 2019.14.25
                    Time: 09:38:05

Sunday,15,October,2017,08:16:28:10074
VCDS Version: Release 11.11.0 (x64)

                Address 16: Steering wheel       Labels: 1K0-953-549-MY9.lbl
Control Module Part Number: 1K0 953 549 CD    HW: 1K0 953 549 CD
  Component and/or Version: J0527           055 0111
           Software Coding: 0001731
            Work Shop Code: WSC 33361 790 00000
           Additional Info: 3T0959537   E221__MFL-URO   H06 0009   
           Additional Info: Geraet 00000
                      VCID: 76E7E2EB01DC22E
5 Faults Found

00576 - Terminal 15
            012 - Electrical Fault in Circuit
00883 - Ignition Switch (D) Terminal S
            012 - Electrical Fault in Circuit
00884 - Ignition Switch (D) Terminal X
            012 - Electrical Fault in Circuit
01744 - Ignition Switch Terminal P (D)
            012 - Electrical Fault in Circuit
00885 - Ignition Switch (D) Terminal 50
            012 - Electrical Fault in Circuit - Intermittent

 

Sunday,15,October,2017,08:17:35:10074
VCDS Version: Release 11.11.0 (x64)

                Address 37: Navigation       Labels: Redir Fail!
Control Module Part Number: 3T0 035 680 G    HW: 3T0 035 680
  Component and/or Version: RNS-MID       H03 5238
           Software Coding: 04000400000400830000
            Work Shop Code: WSC 33361 790 00000
              ASAM Dataset: ------------------------- ------ ()
                      VCID: 346318E3972070E
2 Faults Found

00862 - Antenna for GPS Navigation (R50/R52)
            007 - Short to Ground - Intermittent
             Freeze Frame
                    Fault Status: 00100111
                    Fault Priority: 5
                    Fault Frequency: 1
                    Reset counter: 175
                    Mileage: 210751 km
                    Time Indication: 0
                    Date: 2096.14.30
                    Time: 18:21:47

03138 - Input AUX IN
            011 - Open Circuit
             Freeze Frame
                    Fault Status: 01101011
                    Fault Priority: 5
                    Fault Frequency: 1
                    Reset counter: 135
                    Mileage: 231867 km
                    Time Indication: 0
                    Date: 2103.14.27
                    Time: 08:16:43

 

[LightRain]

Oh my, that's a nice beefy list you have there.

 

Notable that the steering column electronics control unit is flagged with 5 codes and many of the codes relate to what the relays under the wheel control.  I'm going to have to go over the current flow for these circuits and see what I can see. But, I'm away for a few days from today.

 

In the meantime someone may come along and know more about the problem anyway without having to look. For now though, you could do some first, basic checks, to ensure your battery is good and it is charging fine. I would say it is, but if you want to go the self-diagnosis route, better to approach it in a systematic and controlled fashion. Belt and braces would also be worthwhile for something like this.

 

Your car is at least functioning so you don't have any panics. I'm surprised no weirdness happened other than random ticking, and no warnings at all.

 

Oh BTW, what is your engine code? Also, have you had this car from new and has any work been done on it that you know of?

[bigjohn]

Hmm - Is this a good old fashined earth problem? Can cause all sorts of wierd issues

 

Also the "clock spring" can cause problems especially after turning the steering wheel (although this doesn;t make sense with your codes)

 

Worth a check or two...

Edited 15 October, 2017 by bigjohn

[Declan O'Shaughnessy]

@LightRain The battery is pretty new (10 months old) and hasn't been run down or subjected to any stress since it was fitted. I bought the car second-hand in 2010 with 40,000km on the clock. It now has 230,000km on it. The only things to have gone wrong in the last 7 years are a failed DPF sensor and a clogged EGR valve. No work has been done to it at all other than regular services.

 

The only other weirdness I've ever experienced is a multiple lights failure warning, when the MDI informs me that every light is basically faulty. When I do a visual inspection, every light is fine. The problem clears when I turn the ignition off and remove the key, and then restart the car again.

 

The problems electrically with the ignition faults I've known about for a good while. Basically, if I leave the key in the ignition but with the engine turned off (so key in position 0 or I), the power to the console will cycle on and off at random (so radio will turn off and lights come off, as if I'd removed the key). If I jiggle or move the key power will be re-established. It's annoying but never really bothered me enough to need to do anything about it. Nothing has ever happened of a similar nature once the engine is running.

 

@bigjohn The fault codes do say there is a short to ground, but I've no idea how to find or diagnose that (I'm no electrician!).

 

 

[LightRain]

Probably safe to rule out battery problems or aftermarket nonsense then.

 

Some of your issues also seem to relate to ignition, either wiggling it or changing key position etc.. The ignition key and steering column electronics control unit connect to each other, this connection could be the site of some issue along with the units themselves. With VCDS I don't doubt you can check the situation with each circuit of the ignition key, you may have to ask on the relevant topic for VCDS help regarding that.

 

There are many ways you could go. I'd be inclined to check out the ignition module and steering electrics control unit and their interconnection. After making sure the basics are sound (battery, relays and relay sockets).

 

Regarding checking for ground faults. One way is to isolate the circuit, that is unplug it at all of its connections and then test for continuity between battery negative (or other proper ground point) and the relevant wire. I'm not too concerned about that on your major issue, and I think that maybe you have some smaller unrelated issues here too.

[chimaera]

Out of curiosity does this clicking only happen when the indicator is on?

[Declan O'Shaughnessy]

@chimaera No, it can happen at any time. I used to think (years ago) that it was related to the indicator, as that seemed (at the time) to be one way of almost guaranteeing it would happen (i.e. turn indicator on, turn wheel to full lock then release), but these days it can happen before ever the indicator is used on a journey.

 

@LightRain Thanks for all your help. It sounds more like something for an auto-electrician at this point, so I'll probably leave well alone for now. The next time I have it in for a service, I might say it to the garage (but they don't have an auto-electrician on-site - they just recommend a guy who you arrange to come on work at their garage). I'm reluctant to spend money unnecessarily if I can help it.

[LightRain]

That may be the best option. And, to be fair everything appears to be at least functioning and I doubt there is a safety issue with your problems. If you don't have the requisite skills then electrics are best left to people who do, especially for a potentially complex problem like this one. Maybe getting a guy in to diagnose the problem properly can't hurt. You don't have to put any money into a repair if you don't want to and you'd at least know what the problem is and if it could get worse over time.

 

BTW, when/if you do get someone to look at it (or fix it) please let us know what it was and some details, if it's not a problem for you to do so.

Edited 22 October, 2017 by LightRain

[TheRobinK]

21 hours ago, LightRain said:

The ignition key and steering column electronics control unit connect to each other, this connection could be the site of some issue along with the units themselves.

 

On the BMW's I had before my Superb, a worn ignition barrel could cause all sorts of electrical weirdness (lights, parking control sensors, radio on and off, cluster lights etc). It would get worse on older cars - especially ones with owners who had a lot of weight (lots of other other keys, flashlight, penknife, usb with music collection backups etc) hanging off their car key ring. 

[lowedb]

Probably not related, but I get a ticking noise sometimes. I can only hear it with volume turned down on the radio. I'm reasonably certain its the fan on the back of the Columbus, I've probably caused it as I'v got extra wiring in behind there when I added TV and CD changer. It will tick for a bit, then stop, then start again, but it doesn't sound really like a relay, but a motor catching.