Check Lights on Toyota Aqua

[mr.amirmufti]

AoA. Dear members,
I need guidance on these check lights errors on my newly bought Toyota Aqua. Vehicle details are:
Model 2015
Import 2019
Mileage 50K
Fuel Economy 28kmpl(city) 20kmpl (motorway)
Battery cell volts minimum score 14.2 on all cell
EV mileage 1.6kms from full battery to engine again
AC 6 mins on EV
The mechanic checked using the diagnostic tool, and found battery is weak.
However, my concern is

Please guide me if this could actually be weak battery issue.

[capsat]

1 Seat belt latch error
2 Parking Brake error
3 Check engine (CEL)
4 ABS (Antiskid Braking system)
5 VSC (vehicle stability control)
- visit a workshop which can scan your vehicle pull the errors, get a print out. fix 1 by 1

welcome to world of JDM - Scrapyards are only source for used parts, from scrapped vehicles.

primary 12 volt battery in trunk at right side - That shall be tested 1st, and replace it, before anything else is 'replaced'

[mr.amirmufti]

Thank you sir. My mechanic ran scanner and he said that serial 3,4,5 are due to weak cells in the hybrid battery. So, he will take out the battery, put load on it, and will replace the weak cells. I am unsure if he is doing it right

[zee5han]

@mr.amirmufti
No , first get your secondary battery checked (Non hybrid simple which is present in all cars) , it will be below the right side seat in 2nd row .
You would not be getting such good average on a weak hybrid battery , plus your car is only 50k driven (if not meter reversed)
watch this

[mr.amirmufti]

Thank you sir. But what exactly to check in that battery? I mean if the purpose of this battery is only starting the car, then how are these errors related to this battery. Yesterday I changed the seat covers so the worker took out all the seats and then placed them back with new covers, and soon after that I got these signs for the first time, could it be the reason? Like may be he damaged something or some wiring?

[zee5han]

That's most likely the reason as both batteries are present below the 2nd row seats, try taking it one step at a time , Its a pretty non technical way but what I would do in your situation is remove both terminals of the 12V secondary battery wait for 2 mins , then put the terminals on and drive for a short duration, it would reset all the error codes and you can see if all the lights reappear or not.

[mr.amirmufti]

Unfortunately it appeared again after removing terminal from 12V battery.... going for battery load test today. Lets hope for the best InshaAllah

[capsat]

Scanner can / will provide exact codes for problem after 12V battery replacement.

if the 12V primary battery has never been changed since purchase, visit a battery shop, they will test and if necessary please replace it.

HV battery bank cooling fan shall also be cleaned before some chacha hybrid esh-pesh-alyst start experimenting at your risk & cost.

[mr.amirmufti]

So today I went for load test of my hybrid battery. These are the scores on load of 110W on each cell for 5,6,7,8 minutes. After watching few tutorials and expert opinions, and discussion with my mechanic we have replaced 7 weak cells scoring below 6.5. Sharing my experience for fellow users.
Thanks