Had similar issues on dce 100, after replacing the accumulator with a new one, issue still persist. Replaced the sensor on the brake caliper. And was able to use the equipment for more that 72 hours any brake failure, later on handbrake poped up again. Finally solution was to bridge the sensor wire on the caliper. Problem solved.

I have the same code 357 but it's working properly in the morning about 20-30 mins. After the code is shown, the engine can not go over 1500 rpm. I have to reset the code, after that it will come up every 2-3 mins. I have changed the accumulator, sensors, hyd pump, piston seals for both wheels and handbrake. What should i do next?

Please check the control valve. Underneath the main valve bank sometimes bits of dirt block the valve open....

Check pressure in the accumulator, check the engine is not hunting ie. Going into charge , cool mode within 3 seconds if so check charge valve , use a gauge and check the pressures on the data plate if you see the needle jumping consistently when on the brake test port the charge valve is suspect

I had a similar problem and found the brake disk piston letting by.

well i did check at the shop and for this particular model we do not have anything... sorry.

did you manage to get this sorted :0
please check the accumulator charge valve is not bypassing also checkthe main valve bank on the left hand side as you tilt the cab there is an adustable pressure valve on the bottom of the main valve (towards the front of the truck ) remove it and check it is not contaminated

we have some kalmar shop manuals at the shop
i'll see if i can swing by there and check to see if we have this one
maybe there will be some troubleshooting guides in it that will help some.
I'll post back here when i get it.

one other thing to consider is if you bypass the sensor it may see that as the same problem, low accumulator pressure.
Is this accumulator one that is gas charged? i would check that as well. Maybe the pressure in it is low?

Thanks for the reply

Its a fully hydraulic brake system, I have by-passed the sensors to see if we have a faulty sensor, the fault is still the same.

handbrake accumulator?
is this an air operated brake? or manual?
if air operated then:

has the brake system been drained of moisture lately? This could be the result of a gunked up sensor on the accumulator sensor causing it to set the code.
A common problem with air brake systems if they are not maintained properly.

Pull out the sensor and see if it is gummed up and bleed the water out of the air tank. You may have some clean up to do in the air lines and components affected as well.

if manual operated then it could just be a switch adjustment