Instrument cluster and ECU fail - did I wreck them??

[Rupert25]

Hi all,

Just joined, hope someone could help me out here.

I have a X-reg A4-B5 1.8 petrol non-turbo, with the late AVV engine code.

I just had a big MOT bill (new wheelbearing, shocks, springs, track rod ends etc etc.)

I did what I could myself, to save some pennies. One of the items needing doing was the main beam telltale (it's a new MOT requirement). This instrument pack has all built-in LED telltales, so no chance of a simple bulb change. Instead I fitted a remote LED fitted to the dash, wired to the instrument input. That worked perfectly, and I was so chuffed with myself.

But when I went to start the car, the immobiliser cut in after half a second, and I've not been able to reset the immobiliser by anything I've read on forums (disconnect battery and leave it for a few hours, reconnect and try, do the same with a trickle battery charger connected to make sure you have 12.5V, switch on ignition and leave switched on for a few hours. All no good. I checked for visible wiring faults close the instruments, nothing obvious. Main beam telltale still works fine!

No-one except Audi would look at it, as it's an immobiliser issue. So I towed it over there, they charged me £100 to know that the immobiliser was not working (thanks), that their diagnostic can't read the instrument pack nor the main ECU. They spent a further hour confirming that the instruments and the ECU both have 12V supply and 0V (obvious anyway, since the pack lights up and the car fires briefly).They want to replace both, for the full value of the car plus a few hundred.

So it seems the car is scrap, which is a nightmare as I've spent thousands on it (cam belt etc etc don't get me started ).

I probably unplugged and plugged in the instruments with the battery connected, as I was using that to make sure I had the right wire. But I'm 100% sure I didn't short anything out, and that I got the right wire first time.

Buying a scrap instrument pack would be my first idea, but it would need to be the right (rare) engine and model, and of course it would need the key module and to be matched to the ECU of that is still alive.

Anyone got any bright ideas, before I try to sell the car on ebay? Would really appreciate.

Thanks!
Rupert

 

[Sulli79]

When it fires up are all your gauges showing appropriate values? (Other than speed anyway!)
I cant see that you could de sync your keys, but I could be wrong,
i would be double checking all plugs are seated correctly, then check the reader coil for the ignition, it reads the transponder in the key for the immobiliser

 

[adamss24]

Rupert, disconnect the battery terminals and bridge the WIRES together for a few min to clear static. Should take care of your intermitent starting....

 

[Blue_Thunder]

This could be as.simple as one of the connectors not being seated correctly into the cluster. This exact thing happened to me when I had my DIS repaired. I unplugged the cluster again, then made damn sure the 3 connectors were all in properly and it was fine.

 

[Rupert25]

Wow thanks all for such quick replies!
Sulli, yes the gauges all worked inc speedo when I was being towed, instrument lights etc.
Adamss, yes I tried that too, left them connected for a while to de-power everything.
Will check again all plugs in right - they do clip over pretty positively though. But I did unplug them then put them all back, too.
Might have to do it in the car park at audi Norwich - they still have the car!

Cheers,
R

 

[Blue_Thunder]

I thought mine were all clipped in firmly too, but I guess one or two pins weren't right. Reconnected them being careful to ensure connector blocks went onto the pins totally straight and mine fired up first time. Had no issues since.

 

[aragorn]

Yeh, i'd try reconnecting it first off. Its actaully pretty common for folk to have immo issues after taking the cluster out, and reseating the cluster leads usually sorts it.

The fact the cluster wont talk to diagnostics is a good telltale, and Audi wanting to change the ECU is bull****, as the ECU is connected to diagnostics THRU the cluster, so if the clusters not talking, your not talking to the ECU either! Obviously they should know that, but they're just part fitters these days and often dont have a clue.

Worst case, you can get a cluster off ebay for about £50-100 and have a decent auto locksmith reprogram it for not-much-money, or you can buy a Vagtacho lead from ebay and do it yourself. Never EVER take these cars to a main dealer, theres just no point.

Whats the immo light doing? Staying on? Flashing? Going off?

 

[@udi A3]

I have never seen a genuine vagtacho on ebay, and wouldnt recomend a cheapo one for use on an A4. They are hit and miss at the best of times, and can easily cause more problems when writing data.

 

[aragorn]

All your doing is reading the SKC though.

You can do everything else with VCDS!

 

[Rupert25]

I called the Audi garage, they said they had checked the instrument connectors and gave them another jiggle just in case, but no good.

Not keen on using main dealers myself, but none of the independents or electronics people in Norwich would look at immo problems.

So, plan is to tow it back home, give the connectors a good poke myself, then look for a cluster for sale.

Thanks all.

R

 

[Rupert25]

The big red immo light on the pixel display stays on, the little orange car/key light just flashes.

 

[ex911driver]

Rupert if you want me to scan it /look at it im just 15 mins from Norwich Audi ,I will be in work tomorrow if you want it looked at.

 

[ex911driver]

Also the scrapyard next to me has a a4 1.8 in for breaking ,should still have clocks etc in it .

 

[@udi A3]

Worst case, you can get a cluster off ebay for about £50-100 and have a decent auto locksmith reprogram it for not-much-money, or you can buy a Vagtacho lead from ebay and do it yourself.

All your doing is reading the SKC though.

You can do everything else with VCDS!

Vagtacho is fully capable of reading eeproms and programming keys, i assumed you was suggesting the job be completed with vagtacho alone, which is quite possible. As you say, pin reading only with a clone.

 

[aragorn]

The big red immo light on the pixel display stays on, the little orange car/key light just flashes.

Big red immo light?

There is no big red immo light...

What exactly is on the DIS?

 

[Rupert25]

Sorry feel really thick but can't remember- yes its the DIS, I'm pretty sure it was in the manual as immobiliser problem. The car is still at the dealer.

 

[jcb]

IMMO light is in the clock dial itself not on the DIS

don't trust the dealer to have lifted a finger, check the plugs yourself

 

[Broken Byzan]

if the connectors are in correctly then i'd get the immo turned off on the ecu. Costs around 50 - 75. Job done

 

[mojocvh]

Rupert if you want me to scan it /look at it im just 15 mins from Norwich Audi ,I will be in work tomorrow if you want it looked at.

Total awesomeness mate.

Mo.

 

[Rupert25]

All,
I asked the Audi dealer to check the wires and plugs, they called back to say no good. Then they called the next day to say they'd put the covers back on, and the car had started working perfectly again. Collected it this evening, washed and all free of charge.

So, did they check the plugs properly the first time around? Noone knows.

Anyway I'm back on the road, feeling a lot wiser, feeling OK about Norwich Audi, most of all feeling very grateful to all who contributed to this thread.

It turns out the important thing with instruments plugs, like so much in life, is to push them in hard and jiggle them around till the lights go on!

Thanks all!
R

 

[Blue_Thunder]

Should have posted here before taking it to Audi in the first place.

Hope they didn't charge you for following our advice!