I have a 2004 E320 cdi which recently developed a serious electrical fault, after replacing a rear sam I pinpointed that unplugging the big connector from the seat control module (the one labelled CAN on the module) makes everything work perfectly as it should other than the passanger seat controls etc not working ofc.. I bought and replaced the module thinking it was the module but still the same fault, once I plug the big can connector at the front into that module, SRS light comes on, says srs defective, ESP defective, radiator fan spins on full speed constantly, no electronic in the entire car works and the red battery sign comes up saying visit workshop.. the car goes absolutely crazy.. what should I check next?