EQC Wiring Fault

[CoopsSA]

Thought I'd share the problems that I've encountered this week with my EQC. For information, the fault is resolved but I don't know the full details until I see the job sheet on collection tomorrow.


I returned home from work on Friday evening, 50 mile journey, no issues, car had been on charge at work most of the day. Went to go back out later that evening (to collect a takeaway), pressed the start button and nothing. All the auxiliary functions worked - dashboard, phone, radio etc but the car wouldn't physically power up. Thought it was just a blip so switched everything off, locked car, unlocked and tried again. Still nothing. Dash was showing "Drive System Malfunction", big red battery symbol and that the charging cable was connected. Cable wasn't connected but the socket flap was locked and couldn't be opened (despite the car being fully unlocked)

Got straight onto Mercedes through the button in the car - passed over all my details and they said they'd despatch RAC to take a look. (I knew at this stage that normal RAC patrol wouldn't have a hope in hell of sorting it so wasn't expecting much). Within 2 minutes got another call to say exactly this and that I needed a MB Tech, one would be out Saturday morning. As I was stuck at home this was no issue.

MB Tech arrived Saturday morning as planned. RAC liveried but MB Tech. Really knowledgeable and helpful chap. He first suggested a hard reset by disconnecting the 12v battery for 10 mins. That route failed. Next option was to run some diagnostics via his laptop. On doing this, car was registered 2 current faults and 10 stored faults! The current faults were connected to the HV battery and he attempted some updates/upgrades via SCN coding. None of this worked. Recovery to MB was going to be required. Simplistically the car had lost comms and couldn't communicate with the HV battery, sounded terminal!

This is where it gets interesting.

The Tech sorted everything out via MB - recovery company contacted, preferred dealer selected and hire car to be arranged. Received all the necessary emails and texts for this. Recovery company called Saturday afternoon and we arranged for Monday. Europcar rang me Sunday for some information and I was to get a call Monday.

A Class delivered Monday morning by Europcar - nice little car and just the job. Recovery agent arrived Monday in a bid to recover the stricken EQC but despite me telling them on Saturday was unable to do it because the entire car was locked in park. Didn't appear to be anyway to release the motors to enable moving it onto the truck. Whilst you can release the park brake obviously the motors front and rear mean it would have to be lifted. Recovery company would need to get hold of some lifting equipment to do this. Spoke to them and to MB on Monday afternoon and the recovery company were sorting out getting hold of an Eastract. Basically a caterpillar tracked remote control lifting truck which can pick up stricken vehicles. They are like rocking horse poo so it could be a few days until they managed to get hold of it - told MB the hire car would need extending.

Finally got a call on Wednesday that they'd got hold of one, so darted back home in the afternoon to get it done. Fantastic bit of kit and the driver was brilliant, took his time as he didn't want to damage either the car or my drive. Off it went to MB Derby. It's quite scary watching this machine balance your car in mid air whilst it trundles off down the road!



Really wasn't sure how long it would take them to diagnose and fix the problem and was expecting it to be out for the long haul. I knew MB had started to work on it during Thursday as my Mercedes Me app kept pinging me about critical level of 12v battery, doors being open etc. The pings finally stopped mid afternoon and I could see the car had been parked up in their car park. Had they fixed it already?? Turned out they had and I got a call to say all ready to collect.

At this stage all I know is that it was a wiring fault which they've had to rectify. I will be asking for the job sheet so that I can pass it onto my lease company for reference. Once i know more I will update.


We still managed to get the takeaway Friday night BTW!

 

[grober]

Keep us posted as to progress?

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[CoopsSA]

Collected the car on Saturday morning and all back to normal. The technician is going to send me a brief report into what happened/occurred so that I can pass onto my lease company. MB Derby won't share the warranty work job sheet for some reason!?

No issues so far.

 

[Numair Aidroos]

Collected the car on Saturday morning and all back to normal. The technician is going to send me a brief report into what happened/occurred so that I can pass onto my lease company. MB Derby won't share the warranty work job sheet for some reason!?

No issues so far.

Any update Sir?

 

[CoopsSA]

Any update Sir?

It's still working. No further problems. No report from the dealer so I will chase again today.

 

[Petrol Pete]

OP , I am sorry to hear of your problems with your car , I hope it stays sorted. This story highlights one of the (in my opinion) major basic flaws with EV's .

Their total immobility when something major goes wrong -There may be some that can be pushed when dead , but let's stick to this for now - It is clear from the photos that the tracked device used to lift it in this instanced would be completely useless in a great deal of scenarios due to space/access restrictions, owners garage for instance (height) .

Lifting up with a 4 point crane in a multi story/underground car park etc is not going to work. Other options exist such as car skates but they only really work on very smooth surfaces.

The only answer I can see is a 'freewheel disconnect' function . Not sure if that will ever happen without legislation because it will be an admission by the manufacturers of an inherent in built fault.

Some might say that's a worry about nothing , until we realise that the government want nothing but EV's on our roads. At that point the odds of a country lane or narrow one way street in a big city being blocked by an (almost) immovable broken EV for a day rather than an hour become shorter.

 

[CoopsSA]

OP , I am sorry to hear of your problems with your car , I hope it stays sorted. This story highlights one of the (in my opinion) major basic flaws with EV's .

Their total immobility when something major goes wrong -There may be some that can be pushed when dead , but let's stick to this for now - It is clear from the photos that the tracked device used to lift it in this instanced would be completely useless in a great deal of scenarios due to space/access restrictions, owners garage for instance (height) .

Lifting up with a 4 point crane in a multi story/underground car park etc is not going to work. Other options exist such as car skates but they only really work on very smooth surfaces.

The only answer I can see is a 'freewheel disconnect' function . Not sure if that will ever happen without legislation because it will be an admission by the manufacturers of an inherent in built fault.

Some might say that's a worry about nothing , until we realise that the government want nothing but EV's on our roads. At that point the odds of a country lane or narrow one way street in a big city being blocked by an (almost) immovable broken EV for a day rather than an hour become shorter.

Indeed, apparently the recovery agent was saying that the Jaguar I-Pace does have a "disconnect" function under the bonnet which releases everything enabling the car to be freewheeled (as you put it) onto recovery. There didn't appear to be any such functionality on the MB, not that either of us could locate anyway.

To be fair the Eastract would work in a multi storey car park and is designed for exactly that. He was telling me that he had to recover a car from the end of farm track, his recovery truck wouldn't get down so "walked" with the Eastract down the lane and back with the recovered car on it.

 

[Petrol Pete]

I see how the Eastract would work in a multi story car park . But the car park would have to be closed while it made its way up or down to the stricken EV. Bottom line is that without some sort of release/freewheel system the recovery of stranded EV's just got very complicated ....and expensive.

 

[CoopsSA]

Had a further update on the actual problem - not the full details but a brief summary from the tech who worked on it:

Carried out Initial short test of vehicle, Found can-bus network short in DC/DC Converter. Carried out wiring checks from DC/DC Converter to can-bus network connection block, found short circuit in wiring.
Traced short circuit to passenger side kick well, removed kick well panelling and found trapped wires behind panel. Removed wiring from behind panel and repaired. Refitted all removed parts, cleared fault memory and carried out final short test. Retested vehicle, all ok.

So something as a result of manufacturing? Wires looped the wrong way through the chassis?

 

[Numair Aidroos]

Had a further update on the actual problem - not the full details but a brief summary from the tech who worked on it:



So something as a result of manufacturing? Wires looped the wrong way through the chassis?

I had a wiring issue on the w221, 2 years ago. Lucky these cars have computers that send out codes.

 

[Numair Aidroos]

Off topic, took a test of the new Gasoline V6 turbo Q7, it's amazing. Wish I had awaited until it's release. Still no fix for our black mirror.