P128C Code BUICK Possible Causes
- Faulty fuel rail temperature sensor 1
- Fuel rail temperature sensor 1 harness is open or shorted
- Poor electrical connection in fuel rail temperature sensor 1 circuit
How is P128C Code BUICK Repair Done?
Start by checking the “Possible Causes” listed above. Visually inspect the wiring harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
What are the Possible Symptoms of P128C Code BUICK?
- Engine light on (or Service Engine Soon warning light)
What Does P128C Code BUICK Mean?
The fuel supply rail pressure sensor transmits fuel pressure and temperature information via serial data. The internal microprocessor of the fuel supply rail pressure sensor allows 4 separate sensor outputs from a 3-wire sensor. The Engine Control Module (ECM) supplies the fuel supply rail pressure sensor with a 5V reference circuit, a low reference circuit, and an asynchronous signal/serial data circuit. The asynchronous signal means communication only goes from the fuel supply rail pressure sensor to the ECM. The ECM decodes the serial data signal into separate voltages that are displayed on a scan tool as fuel temperature sensor, fuel rail pressure sensor, and fuel rail pressure sensor 2 voltage inputs.