Battery replaced, no Stop/Start etc

[fr3manCitroen]

Citroen C4 GP, year 2015.
Had the battery replaced by local specialist, but now have 'Service' light on, 'Engine Fault' suggested and 'ECO OFF' and can't activate. The fitter / supplier has tried to reset the system (BSi) by the procedure suggested in this forum, "BSi Reset / Battery Disconnection / Reconnection" viewtopic.php?p=601679#p601679, but unfortunately this did not work.

Today my local Citroen Main Deal said they can't look at the car to do a diagnostics test until end of Jan 2023 and charge £139 just to complet the test.

Any advice or suggestions, please.

[GiveMeABreak]

Yes, ignore the issue. As long as the battery was replaced for a like for like type and specification. The vehicle is designed to work with the correct battery type I.e for stop start systems this will either be an AGM or an EFB battery (post up your VIN if unsure what you are supposed to have and I’ll tell you).

As long as all the above are correct, then it can take 24 hours or so for the new battery and the ‘ Battery Charge Status Unit’ to calibrate the new battery, during which the stop start system may not operate.

[fr3manCitroen]

GiveMeABreak, thanks for your comment.
The first replacement battery was faulty, a second replacement battery was fitted, but it appears both where wrong batteries (Duracell Extreme AGM, Cranking Power 720). Now had a third battery fitted by Citroen specialist, but still no Stop/Start, Service light remains on and Engine Fault Have the vehicle repaired flashing up on starting.
Now not sure what is needed, but I'm going back to the Citroen specialist.

[fr3manCitroen]

GiveMeABreak. Hi Marc,

had a diagnostic test again this morning and the fault Code U1218 will not clear/reset. I would post my VIN number but don't know how to hide it from public.

[Hell Razor5543]

It will automatically be obscured so that only Forum staff can read it, like this; VF7**************[VIN obfuscated, can be read by forum staff] (I am not Forum staff).

[fr3manCitroen]

GiveMeABreaak.

VIN VF7**************[VIN obfuscated, can be read by forum staff]

[fr3manCitroen]

Thanks Hell Razor5543.

[Hell Razor5543]

You are welcome. I hope you manage to get her sorted out.

[GiveMeABreak]

GiveMeABreak. Hi Marc,

had a diagnostic test again this morning and the fault Code U1218 will not clear/reset. I would post my VIN number but don't know how to hide it from public.

Right, now we know what vehicle you have there could be another reason.

The Stop Start system employed on this vehicle does not rely on the main battery alone. You have an ultra-capacity or energy accumulator fitted that works with regenerative braking to restore and recharge the accumulator, which is like a second battery.

So your fault may not lie with the main battery at all.

U1218 is an electrical issue that can relate to many systems on the vehicle. In some cases where the 'Have the engine repaired' message is coming up it can be a simple matter of the exterior air temperature sensor going faulty. This is the little nipple located underside of the passenger wing mirror, but other equipment also relies on the data received from it, including the Air Conditioning and the Stop Start systems.

So I would check that the sensor is operating correctly and that there are no breaks in the wires to the sensor inside the door card / mirror.

However if it's anything to do with the energy accumulator, be wary as these hold high voltage and must be properly discharged before any work is carried out, so best left to the dealer or other specialist who knows these systems and how to check them.

[fr3manCitroen]

GiveMeABreak. Hi Marc,
Thanks for your response, most helpful. I am grateful.
The info in your reply is very interesting, I had no Idea my car had such equipment. I'm old school, back in the 1960's I and a friend built a mini getting a shell from a breakers yard and spending month search breakers for all the parts/components.
regards, Dennis.

[GiveMeABreak]

I should also mention after further checks that if fault code P1A9B 22 is present, with the same messages you are getting then there are cases for some of these models where an engine ECU software update is required, so it may be simpler and more cost-effective in the long run to get the dealer to properly check with their diagnostics.

[DarthPyross]

GiveMeABreak. Hi Marc,
Thanks for your response, most helpful. I am grateful.
The info in your reply is very interesting, I had no Idea my car had such equipment. I'm old school, back in the 1960's I and a friend built a mini getting a shell from a breakers yard and spending month search breakers for all the parts/components.
regards, Dennis.

Hello, do you have any updates on this?