Engine stopped

[Gregory A]

Hi help required please!

 

I have a 2014 Audi Q7 TDI S line. It needed some attention, the car was running for about an hour in the drive after not running for 12 months (it did start first time). Then it just stopped. I had identified a slow start issue and noticed the earth cable under the bonnet attached to the block and chassis had partially melted, so I replaced and recarged the battery to full (new battery AGM)

The engine subsequently did turn over however intermittently starter just 'clicks' and intermittently wont start either, just cranks over at a good speed, (fuel supply feels like) battery is good, any help would be welcome?

 

Best

Edited October 1 by Gregory A

[Stevey Y]

1 hour ago, Gregory A said:

Hi help required please!

 

I have a 2014 Audi Q7 TDI S line. It needed some attention, the car was running for about an hour in the drive after not running for 12 months (it did start first time). Then it just stopped. I had identified a slow start issue and noticed the earth cable under the bonnet attached to the block and chassis had partially melted, so I replaced and recarged the battery to full (new battery AGM)

The engine subsequently did turn over however intermittently starter just 'clicks' and intermittently wont start either, just cranks over at a good speed, (fuel supply feels like) battery is good, any help would be welcome?

 

Best

Hi if the earth cable was melted you have a bad short somewhere my guess would be the starter, quick question when you replaced the battery did you re code it.

Steve.

[Gregory A]

Hi Steve, many thanks for the response, i didn't re code no, albeit I do have a basic OBD diagnostic?

 

PS the electric engine cooling fans kick in as the engine spins over when it does try and start.

[Stevey Y]

2 minutes ago, Gregory A said:

Hi Steve, many thanks for the response, i didn't re code no, albeit I do have a basic OBD diagnostic?

 

PS the electric engine cooling fans kick in as the engine spins over when it does try and start.

Hi unfortunately in my experience 99% of basic code readers are not worth trying on post 2008 vehicles you would see codes if you went up a couple of levels say Snap on or VCDS, the cheapest and most effective is OBD Eleven at sub £100 this will also enable you to code the battery which is a MUST or the the battery will fail as fast as you can blink, I dont know if your plan is to keep the car but I wouldn't mind betting that a scan with a decent reader would throw up a pandoras box of codes most of them irrelevant but would include the codes you need to solve your problem.

Steve.

[Gregory A]

Steve invaluable information there.

 

Apprecitate your help, I'll order the OBD eleven and run through further tests.

 

I will keep the car as it is pretty low mileage 75k, the damage I believe has been it being sat for 12 months gathering damp.

 

 

[Stevey Y]

On 10/1/2024 at 1:34 PM, Gregory A said:

Steve invaluable information there.

 

Apprecitate your help, I'll order the OBD eleven and run through further tests.

 

I will keep the car as it is pretty low mileage 75k, the damage I believe has been it being sat for 12 months gathering damp.

 

 

Hi if you keep us updated the information will be invaluable to other members and myself.

Steve.

[Gregory A]

15 hours ago, Stevey Y said:

Hi if you keep us updated the information will be invaluable to other members and myself.

Steve.

Hi Steve after checking the ODBeleven, as you stated a lot of faults however, the main one being ECM (engine control module) Fault code 01314 'intermittent' I kind of had an idea it maybe that failing. Replacement unfortunately. Is there any merit in purchasing second hand unit? PS milegae previously stated was incorrect, 127k miles currently.

[Gregory A]

See below Steve.

[Gregory A]

I've replaced the media circuit board too as it was not working hence the other codes above.

[Stevey Y]

6 hours ago, Gregory A said:

Hi Steve after checking the ODBeleven, as you stated a lot of faults however, the main one being ECM (engine control module) Fault code 01314 'intermittent' I kind of had an idea it maybe that failing. Replacement unfortunately. Is there any merit in purchasing second hand unit? PS milegae previously stated was incorrect, 127k miles currently.

Hi I would be checking the module itself before replacing it most of the time its down to corroded/bad contacting pins in the plug units a quick hose down with a good contact cleaner and then reassembly often works wonders, working on the intermittent bit the ECM does not have the ability to self diagnose therefore it only has two modes working and dead, worst case scenario you can haul it out and send it to ECU Testing I have used them multiple times for different vehicles the fair bit with them is they will tell you if its damaged internally, if its repairable even if it isn't they will give you best advice on where to get another unit, I know there are people who sell refurbished units that are just plug in and play, if you buy a second hand unit it will need recoding and may only have a limited service life, try cleaning the plugs to the unit first you may well save a few bob.

Steve.

[Gregory A]

Top tip Steve. I'll do that next and update the thread.

 

Best

[Gregory A]

Hi All, the ECU was at fault. I imported a second hand ECU which presented a whole load of issues re mapping the original data off the old ECU, this was unsuccessful as the immobiliser function could not be bypassed by the high street mapper, I had to get a specialist to remap the immobiliser, its now fixed but has cost best part of £900.00 (inc 2nd hand ECU) still cheaper then a new ECU. 

You live and learn.

Edited December 5 by Gregory A