P1261 - Cylinder #1 High To Low Side Short
- Faulty Fuel Injector
- Faulty Fuel Injector Interface Module
- Fuel Injector harness is open or shorted
- Fuel Injector circuit poor electrical connection
Check valve cover wire harness connections first, including under the valve cover.
- Engine Light ON (or Service Engine Soon Warning Light)
A fault is detected by the fuel injector interface module in the secondary (rearward) fuel injector circuit