P1263 Cylinder #3 High To Low Side Short

Possible causes

– Fuel injector No. 3 output circuit open or short to ground.
– Injector.
– Faulty Engine Control Module (ECM)

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P1263 Description

Indicates a low voltage condition exists at the injector output of the NG module for cylinder No. 3 when high voltage is expected.