02 Nissan quest-code reader cannot communicate w/ vehicle. DLC has power, CEL is on.

Question

Van is not running in closed-loop aka limp-home-mode. CEL is on and several different code readers unable to communicate w/ ECU. Cig lighter fuse is good, and as mentioned, the data link connector has power (it powers on the scanner).

Answer 1

Check all the fuses, there is more than one fuse powering the ECU and the DLC. Just for the DLC there are 3 fuses (Fuse #4, #29, and #34). Usually when the readers cannot communicate the problem is a fuse.  If all the fuses are OK, then you have to check the wire from the data link connector to the ECU, for your vehicle model is the "Blue/White" , "Yellow/Green" wire. If the fuses and wires are OK, you may have to have the dealer check for codes with the Nissan CONSULT.