Porsche Macan Forums

I was on my way to Heathrow yesterday (120 miles each way and almost all motorway). About 50 miles into the outward journey there was a "bong" and a warning appeared "AdBlue fault: No Engine Start in 600 miles). When I acknowledged the fault, as well as minimising in the bottom right of the right hand dial, the range reading disappeared to be replaced by a yellow spanner with AdBlue fault and 600 alongside it.

Ten miles further into the journey and there was another warning "Engine Control Fault: Consult Garage: Driving Permitted". When I acknowledged this warning the bottom right diagram changed to a yellow triangle with a figure 2.

Stopped at the Cherwell Valley services for a comfort break and both warnings were there on restart. Closer to London and another "bong" and the 600 changed to 550.

Dropped youngest son off at Heathrow. Engine shut down for around 50 mins and all warnings present on restart. A short distance into the return journey and 550 reduced to 500. Stopped at Cherwell Valley for a break and on restart AdBlue warning briefly appeared and then cleared. Engine control fault still there and is still present today. Car booked into OPC after the Bank Holiday.

Anybody else experienced the "AdBlue fault"? This is not the same as AdBlue low and in fact I'd fairly recently topped the tank up. Now the car is out of warranty, it will be interesting to see how much it costs.

How much Adblue did you put in when you topped up the tank ? You might not have put enough in to reset the system.

mark-yorkshire wrote: ↑Tue May 21, 2019 1:07 pm How much Adblue did you put in when you topped up the tank ? You might not have put enough in to reset the system.

I'd put in 10 litres last August before a holiday. In April this year, I attempted to put another 10L in and could only manage 8. I'd done about 1K miles since then and had put the last two litres from the container in a week ago. At the time I tried to put in the 10L, I was surprised that the tank was not lower because I had done 15K miles with only 10L added since the AdBlue tank was last filled to max.

My first thought when the warning came up was there was something up with the delivery system. It remains to be seen whether the engine control fault is linked to the AdBlue fault as the latter has cleared.

I had it a couple of years ago.

Porsche Assist picked it up and took it to the OPC. Turned out it was a failed AdBlu sensor. Apparently the sensor 'talks' to the ECU every 10 minutes.

As it failed, the engine didn't 'hear' from it, hence the faults. OPC said they hadn't come across it before but that was 2017. Simple 1 day fix and filled up with AdBlu for gratis as they had to empty the tank to fit the new one.

BigPhil

On-Track wrote: ↑Tue May 21, 2019 1:17 pm

mark-yorkshire wrote: ↑Tue May 21, 2019 1:07 pm How much Adblue did you put in when you topped up the tank ? You might not have put enough in to reset the system.

I'd put in 10 litres last August before a holiday. In April this year, I attempted to put another 10L in and could only manage 8. I'd done about 1K miles since then and had put the last two litres from the container in a week ago. At the time I tried to put in the 10L, I was surprised that the tank was not lower because I had done 15K miles with only 10L added since the AdBlue tank was last filled to max.

My first thought when the warning came up was there was something up with the delivery system. It remains to be seen whether the engine control fault is linked to the AdBlue fault as the latter has cleared.

I would only put in Adblue when required and not be temped to top up a while later.

I visited Silverstone OPC earlier today to book a 4-year (major) service for August. Co-incidentally, as I pulled away from the dealership I experienced this AdBlue/engine control fault lights. I went straight back, left the car with them whilst we went for lunch in Towcester, and they diagnosed a faulty adblue sensor. It's booked in for next Tuesday once the part arrives from Germany.

Incidentally, Silverstone OPC is currently being renovated with quite extensive building work - I think the grand opening is scheduled for September.

As an update on my situation: OPC drained the AdBlue tank, reset the system and told me all would be well. Since then I have had four re-runs. Latest was yesterday. When I start the car up later today I'll find out if system has reset itself completely or the engine control fault light is still on.

Car is going in four four year service on Tuesday so will be ringing OPC to say I want a proper solution this time. Given your problem and Big Phil's, my money is on the AdBlue sensor.

On-Track wrote: ↑Wed Jul 10, 2019 9:43 am Given your problem and Big Phil's, my money is on the AdBlue sensor.

Yes I was specifically told that it was a faulty AdBlue pressure sensor, and that the engine control light is directly related.

Just collected my car this morning from Silverstone OPC. They initially replaced the pressure sensor but that didn't clear the fault, so they had to order an AdBlue pump and fit that. Hence took a couple of extra days but all is now sorted

I had a new AdBlue pressure sensor fitted on Wednesday. I now know that the sensor is an integral part of the hose between AdBlue tank and exhaust and costs £160, plus a new tankful of fluid and the labour.

The car is one year out of warranty. If nothing else goes wrong in the next twelve months I will have saved compared to extending the warranty. Time alone will tell if not going for the extension was a good move or false economy.