• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Fuel is drawn from the fuel tank through the fuel heater, then to the fuel injection pump. Fuel temperature is monitored by the fuel temperature sensor, which is located in the fuel return line on the engine. The engine control module (ECM) supplies 5 volts and a ground circuit to the sensor. When the ECM detects a fuel temperature above the pre-determined value, this diagnostic will fail, but will not turn the malfunction indicator lamp (MIL) ON.
• | The ignition is ON. |
• | DTC P0168 runs continuously within the enabling conditions. |
• | The fuel temperature sensor is above 113°C (235°F) for more than 10 seconds. |
• | DTC P0181, P0182 or P0183 are not set. |
DTC P0168 is a Type C DTC.
• | DTC P0168 is a Type C DTC. |
• | The message center displays Reduced Engine Power. |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
The Fuel Temperature and ECT Temperature parameters should closely match each other when the engine has not been started and soaked overnight.
Important: Fuel temperature overheating may be cause by a fuel heater element that is stuck on. Refer to Fuel Heater Always On.
With ignition ON and the engine OFF, observe the Fuel Temperature and ECT Temperature parameters with a scan tool.
⇒ | If the temperatures do not closely match each other when the engine has cold soaked overnight, test for a skewed fuel temperature sensor. Refer to Component Testing in the diagnostic. |
⇒ | If the fuel temperature sensor is skewed, replace the sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.