I have Honda Civic with D16W9 engine and an automatic transmission. I've driven it since 2004, after purchase. The car has been very good with minor collapses till now. Lately, a check engine light has appeared. After scanning for code, a P1263 has been obtained. I have searched for P1263 on the internet & contacted various electricians and the description i have obtained so far is ''Cylinder #3 High To Low Side Short: A fault is detected by the fuel injector interface module in the secondary (rearward) fuel injector circuit''. I need to know the meaning of SECONDARY FUEL INJECTOR CIRCUIT because neither the service manual nor the technicians are clear in this regard. If you can identify the circuit on the wiring diagram, it will be very helpful. I have contacted local dealerships as well but no one has come up with a solution so far.

 

best thing to do is to swap the injector with one next to it and see if the code follows the injector