When using china clone mb star c4 sd connect Multiplexer, it could not link to the car computer, MB SD Connect C4 offered a message, saying like “check cable connection / turn ignition on”. Then tried again, clone SDconnect compact 4 multiplexer cannot access OBD2 portAccording to customer’s feedback that he failed to access to the diagnostic OBD port when tried to use sd connect c4 read errors code from Benz SRS system. The system prompted an error message “check cable connection/turn ignition on”.Possible Reason:The error lies on the SD Connect C4s battery.?Solution from obdtool.co.uk:1) Check and record your MB SD Connect C4 multiplexer battery
2) Hook up a digital multimeter to set it to the direct current
3) Get two t-pins and plug them into the OBD socket at PIN 5 and PIN17 position
4) Put your positive lead to PIN16 and negative lead to PIN5.
5) Write down the voltage on the digital multimeter
6) Check if the voltage you from PIN16 and PIN 5 is same in step 1.
7) Find the light green wire with a blue tracer band of PIN10 of the OBDII connector.
8) If the voltage differs in step 1 and step 6, the problem is probably with your battery.
9) If the battery is damaged or broken, please replace your battery.This is from obd tool website technical support: How to Slove MB SD C4 Cannot Access OBD2 Port
2) Hook up a digital multimeter to set it to the direct current
3) Get two t-pins and plug them into the OBD socket at PIN 5 and PIN17 position
4) Put your positive lead to PIN16 and negative lead to PIN5.
5) Write down the voltage on the digital multimeter
6) Check if the voltage you from PIN16 and PIN 5 is same in step 1.
7) Find the light green wire with a blue tracer band of PIN10 of the OBDII connector.
8) If the voltage differs in step 1 and step 6, the problem is probably with your battery.
9) If the battery is damaged or broken, please replace your battery.
