The car has quite a simple instrument cluster, and a single CAN Bus network. The instrument cluster is mostly simple signals but a few are required to keep it happy. The cluster has a dynamic oil pressure warning, meaning that over ~800rpm the oil pressure pin needs pulling to ground otherwise the cluster shows an error and beeps. The RPM signal is on the CAN Bus, ID 0x280 where Bytes 2 and 3: RPM*4, I'll have my custom ECU replacement send out this signal. 2 Other CAN BUS messages appear to be required: 0x 488, this contains a counter, Byte 0: Counter 0-F << 4 + 8, Byte 1-4: 21, 21, 7E, A6, Byte 5-6: 0, Byte 7: Counter 0-F << 4 0x580, this also contains the counter and some static data, Byte 0: 0x80 + counter 0-F, Byte 1, 2: 0, Byte 3: sequence 0x0f, 0x28, 0x7f, 0x28, Byte 4: sequence 0x1e, 0x10, 0x00, 0x10, Byte 5: sequence 0x70, 0x56, 0xf0, 0x56, Byte 6: sequence 0x0c, 0x48, 0xa7, 0x48, Byte 7: sequence 0x46, 0x90, 0x28, 0x90
My blog covering a budget conversion of a VW Beetle to electric power, using parts from salvage.