u/Professional-Bid1543

Hi guys,

Wanted some advice/help.

I had my 2019 VW Golf GTI Performance 55000 miles Automatic just suddenly lose power on me while driving last week, still had the dash on and lights but couldn’t gain power and shift gear to D. Opened the bonnet and noticed my relay was making a clicking noise, I replaced my relay with a genuine VW part brand new and still same clicking noise & wouldn’t start.

Had a few mechanics including one with official VW scanning tablet come out and they said that the ECU is faulty/damaged.

I had an auto electrician come out too who inspected all the wires and electrical components and he took the ECU out and showed how it rattles once shaken, as if something is inside loose.

He also scanned the vehicle and came up with the following fault code P086A00- ECM, PCM Power relay deenergized performance too early.

Also, when the relay is in the vehicle the brake lights are off, whenever I remove the relay all of a sudden my brake lights come on as if someone is pressing the brake. It is really weird.

I sent my ECU in for them to repair but unfortunately they couldn’t test it and therefore couldn’t repair it.

I am not stuck with either buying a brand new ECU (£1700 quote from VW)

Or, buying a used one for £350 which includes flashing over previous data from my damaged one and all coded correctly.

I need some advice please, how reliable are used ECUs given they have been coded correctly?

P.S, my car was NEVER mapped, no mode, & I drive normally don’t rag it.

Hi Guys,

Hoping someone could help me out here as I have no idea whats going on.

For context, was driving on Thursday and all of a sudden my car lost power, literally was unable to give it gas while driving, luckily i pulled up on the side of the road. Tried restarting the car but it wouldn’t even crank, just the dash would come on with a lot of electrical faults.

I opened the hood and my relay was making a concerning clicking noise, thought it was the relay that was gone soI replaced it, still even with the new relay the noise continues and the car still doesn’t start.

I had 2 mechanics come out to check the car, the battery and everything was fine, one of my them scanned the car and was unable to see where the issue originated, he said he needs VW specialist with their equipment to scan it and see whats going on.

The other mechanic also said the same thing but mentioned there was a CAN fault or something and that the car needs a software update as the car is not speaking to each other and that a VW specialist with their tablet needs to scan the car.

They also tried everything, battery reset, jump start etc.

The car has gone into safe mode or something, loss of all electrical stuff like power steering, and getting a lot of faults on the dash.

Anyone know what the actual issue is here and what I can do? Is it an expensive fix?

FYI the car is stock, no modifications, was recently serviced including gear box service and sits at 58k miles. I drive normally and don’t rag it at all.