P128D CADILLAC Code Possible Causes
- Faulty Fuel Rail Temperature Sensor 2
- Fuel Rail Temperature Sensor 2 Harness is Open or Shorted
- Poor Electrical Connection in Fuel Rail Temperature Sensor 2 Circuit
How is the P128D CADILLAC 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 P128D CADILLAC Code?
- Engine Light On (or Service Engine Soon Warning Light)
What Does P128D CADILLAC Code Mean?
The Fuel Rail Pressure Sensor transmits fuel pressure and temperature information via serial data. The internal microprocessor of the Fuel Rail Pressure Sensor allows 4 separate sensor outputs from a 3-wire sensor. The Engine Control Module (ECM) supplies the Fuel Rail Pressure Sensor with a 5V reference circuit, a low reference circuit, and an asynchronous/serial data signal circuit. The asynchronous signal means communication only goes from the Fuel 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.