Engine-Codes - Gmc - P128C GMC

P128C GMC - Fuel Rail Temperature Sensor 1 Signal Message Counter Incorrect

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

P128C GMC Possible Causes

  • Faulty Fuel Rail Temperature Sensor 1
  • Fuel Rail Temperature Sensor 1 harness is open or shorted
  • Fuel Rail Temperature Sensor 1 circuit poor electrical connection

How do I fix code P128C GMC?

Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

Cost of diagnosing the P128C GMC code

Labor: 1.0

The cost of diagnosing the P128C GMC code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.

Possible Symptoms

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

P128C GMC Meaning

The fuel rail pressure sensor transmits fuel pressure and temperature information by serial data. The fuel rail pressure sensor internal microprocessor allows 4 separate sensor outputs from one 3 wire sensor. The Engine Control Module (ECM) supplies the fuel rail pressure sensor with a 5 V reference circuit, a low reference circuit, and an asynchronous signal/serial data circuit. The asynchronous signal means communication is only going from the fuel rail pressure sensor to the ECM. The ECM decodes the serial data signal into separate voltages which are displayed on a scan tool as the voltage inputs from the Fuel Temperature Sensor, Fuel Rail Pressure Sensor and Fuel Rail Pressure Sensor 2.

P128C GMC More Information

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