Diagnostic group

Cooling & Temperature Codes

Coolant temperature, warm-up, and thermostat codes that can affect emissions, driveability, and overheat diagnosis.

P0115-P0119, P0125-P0128

How to Use This Group

Start by reading all stored and pending codes together. A companion lean, misfire, EVAP, or oxygen-sensor code can change which test should come first.

Codes in This Group

P0128 Coolant Thermostat Below Regulating Temperature The engine is taking too long to reach the expected coolant temperature.

Sources

  1. SAE J2012DA Digital Annex of Diagnostic Trouble Code Definitions
  2. 1996 Ford Mustang Owner Guide