The 59B70 is from a later 16V Vitara, the processor is an H8/532 variant (MH5328CP10).
This version is a masked ROM, the datasheet does not describe any method of reading the memory but there
are two undefined operating modes, one of which may be a Special Test Mode. There are other versions of this ECU
that use a One Time Programmable (OTP) memory, OTP devices can be read using a standard EPROM programme with a
readily available adapter. Despite the name 'One Time Programmable' these chips can be reprogrammed but can not be erased
so address overloading must be used to relocate tables when remapping.