safe mode problem after heat .

Hi all,

I have an annoying problem in my car C3 2003 1.4 with the auto gearbox, in the morning i don't have any problem till i spend many time in the traffic then the gear didn't change to 3 level smoothly and car has been juddering and bumpy and the safe mode appears when i stop and start the car work but for a while, i changed the oil , piston and refinery in the gearbox but no luck !!!.

this image when i diagnostic the car .

No one help me

ahmedalmulki wrote:this image when i diagnostic the car .

Which oil did you refill the gearbox with?

i don't know which oil the garage use , but after i reset the fault and diagnostic again after 1 week i get only one error "Slipping (clutch \ brakes)" how can i solve this error ?

Thanks for your supports .

ahmedalmulki wrote:"Slipping (clutch \ brakes)"

Slipping clutch and brakes are major problems with the gear box, possibly the wrong oil is used?

This video shows you the clutches and brake bands in an automatic transmission

You can see they are an integral part of the gearbox. If these are worn, it may be easier to replace the whole auto box, than repair your broken one.

Ok thanks C3driver52 for your support , but what oil must i use for my car and how can i know my oil is bad or no , and from where i can buy new clutch and brakes ?

ahmedalmulki wrote:what oil must i use for my car and how can i know my oil is bad or no , and from where i can buy new clutch and brakes ?

https://citroenc3owners.com/c3-automatic ... n-t56.html

The automatic gearbox fluid for the AL4 is Esso ATF 4HP20-AL4 or this - Esso LT 71141 or This - mobil ATF 4HP20-AL4


You can tell if the oil is bad (and the box itself) from the colour of the oil:


Good (new) on the left, contaminated (old) on the right.


https://citroenc3owners.com/c3-automatic ... 85-10.html

Or from the symptoms of gear changes not working as they should.

I don't know where you would buy the parts, its easier just to fit a second hand gearbox than try to repair a damaged one. I would expect a company that specialises in reconditioning automatic gearboxes could source the parts for you, but its not a job I would like to have to do and replace the brake bands and clutches when there are so many C3s available for scrap parts. It seems a bit of an overkill to fit brand new clutches and brake bands to a 10 year old box, how many years are left in the car?

Thanks again , but i want to know way the all problem appears only when the car is heat , and the car it working great when it cold !!

ahmedalmulki wrote:Thanks again , but i want to know way the all problem appears only when the car is heat , and the car it working great when it cold !!

I don't know because I can't see inside the gearbox, but I do know that oil changes its viscosity and becomes thinner as the temperature increases. I would imagine that when the oil is cold its has enough viscosity to work correctly, but when it warms up the viscosity changes and is not thick enough to work correctly in what could be a worn out gearbox.

https://www.kewengineering.co.uk/Auto_oils/oil_viscosity_explained.htm wrote:What is Viscosity?

Viscosity, by definition, is an oil’s resistance to flow and shear. It is the single most critical physical property of the oil as it affects both the wear rate and the fuel efficiency.

Water is a low viscosity fluid; syrup is a high viscosity fluid. With oil, like syrup, as you increase the temperature, the viscosity lowers, meaning it flows faster, or more easily.