Diagnostic advice

lazyman

Hi
I bought a ford cmax two months ago from a Renault garage, it is still in warranty.
10 days after I got it the car would not start when we came back to it in the car park on a day out.
There were 6/7 red faults on the display such as engine failure, power steering failure, key not found, brake failure etc
We got it brought home by tow truck and of course when we went to start it at home it worked fine
Rang the Renault dealer who looked at it bit said there was no fault on screen and their diagnostic machine didn't read any faults
All was good until yesterday when it happened again, this time we left it for 5 minutes and when we turned it on the faults had disappeared
There obviously is something wrong so I am wondering should a diagnostic machine be able to read a fault if it is not on the car screen?
Would the ford dealer have better technology?
Thank you and sorry for the long post.

Tropheus

Do you know how old the battery is? A weak battery can cause all sorts of problems for modern electrics.

lazyman

Tropheus wrote: »

Do you know how old the battery is? A weak battery can cause all sorts of problems for modern electrics.

I don't it's a 151 so presume it's 4 years old
Thanks

biko

As long as car is in warranty I wouldn't even bother diagnosing it myself.
Keep bugging the dealer until all issues are fixed. Don't give up.

lazyman

biko wrote: »

As long as car is in warranty I wouldn't even bother diagnosing it myself.
Keep bugging the dealer until all issues are fixed. Don't give up.

Ya I will do but if there is an underlying fault but is not on the car display, should the diagnostic machine read it?

bazz26

Did the Renault dealer you bought off stick it on their diagnostic computer or send it to a Ford dealer to be scanned? The reason I ask is that if it's a Ford specific error then it's very unlikely a Renault dealer who would probably only have Renault specific diagnostic tools that may well have not picked up Ford specific diagnostic codes/errors.

mickdw

Faults will surely be stored.
Take no crap from the Renault dealer.
I'd get a diagnosis myself from ford just to cut off the Renault dealer when they say no issues showing now - it's working now.

lazyman

bazz26 wrote: »

Did the Renault dealer you bought off stick it on their diagnostic computer or send it to a Ford dealer to be scanned? The reason I ask is that if it's a Ford specific error then it's very unlikely a Renault dealer who would probably only have Renault specific diagnostic tools that may well have not picked up Ford specific diagnostic codes/errors.

They used their Renault machine but I'm going to insist that they send it to the ford one two miles away, paid enough for the car without having to put up with this.

corks finest

lazyman wrote: »

Hi
I bought a ford cmax two months ago from a Renault garage, it is still in warranty.
10 days after I got it the car would not start when we came back to it in the car park on a day out.
There were 6/7 red faults on the display such as engine failure, power steering failure, key not found, brake failure etc
We got it brought home by tow truck and of course when we went to start it at home it worked fine
Rang the Renault dealer who looked at it bit said there was no fault on screen and their diagnostic machine didn't read any faults
All was good until yesterday when it happened again, this time we left it for 5 minutes and when we turned it on the faults had disappeared
There obviously is something wrong so I am wondering should a diagnostic machine be able to read a fault if it is not on the car screen?
Would the ford dealer have better technology?
Thank you and sorry for the long post.

99 percent battery problem