P128E Code GMC Possible Causes
- Faulty fuel rail pressure sensor
- Fuel rail pressure sensor harness is open or shorted
- Poor electrical connection in the fuel rail pressure sensor circuit
How is GMC P128E Code Repair Performed?
Start by checking the “Possible Causes” listed above. Visually inspect the wiring harness and associated connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
What are the Possible Symptoms of GMC P128E Code?
- Check Engine Light On (or Service Engine Soon Warning Light)
What Does GMC P128E Code Mean?
Under certain engine operating conditions, the Engine Control Module (ECM) monitors the actual fuel rail pressure reported by the fuel rail pressure sensor and compares the value to a set programmed value. If the values are outside the calibrated range for a defined duration, DTC P128E will set.