In 1979, a modernized version of the GCBA 6/32 car, marked with the symbol 004M, was put into production. The changes concerned mainly the water and foam system and fittings. Electro-pneumatic control of the fire truck pump from the driver’s cabin was also introduced. The vehicle received a new DWP24 cannon manufactured by the Fire Equipment Plant in Łódź, which replaced the imported Rosenbauers. At the same time, the production of a variant equipped with 2 cannons was discontinued. From 1982, the vehicle was built on the modernized Jelcz P325 chassis. The Jelcz 004M car was produced in 1979-1992. For more than two decades, it has been the standard GCBA type unit used by fire departments.