Circuit Description
In order to reduce the engine temperature the PCM has the ability to disable a number of fuel injectors during an engine over temperature condition. The PCM considers the engine over temperature whenever the ECT reaches a predetermined temperature. This DTC sets in order to show that the PCM detected an over temperature condition and that the system engaged the protection mode.
The PCM sends the Instrument Panel Cluster (IPC) engine coolant temperature information via the class 2 circuit. This information is used for controlling the coolant temperature gauge and for displaying a message when the coolant temperature is out of the normal operating range. The IPC displays a message when the engine coolant temperature is greater than 121°C (250°F).
Conditions for Running the DTC
| • | DTCs P0117, P0118, P0125 are not set. |
| • | The engine is running. |
Conditions for Setting the DTC
| • | The engine coolant temperature is greater than 132°C (270°F). |
| • | The above conditions present for greater than 10.0 seconds. |
Action Taken When the DTC Sets
| • | The PCM illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails. |
| • | The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame and/or the Failure Records. |
| • | The message center displays a message. |
| • | The PCM alternately disables four injectors. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A last test failed, or current DTC, clears when the diagnostic runs and does not fail. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Use a scan tool in order to clear the MIL and the DTC. |
Diagnostic Aids
Important: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.
Important:
• The PCM enables the Engine Coolant Over temperature mode when
coolant temperature exceeds 132°C (270°F). Engine damage still could
occur if the customer operates the vehicle too long in an overheat condition.
Ensure no engine mechanical conditions exists after the overheat condition
is repaired. • If an overheating condition exists, repair the overheat condition
and change the engine oil and filter. • Using the Freeze Frame and/or Failure Records data may aid in
locating an intermittent condition. If you cannot duplicate the DTC, the information
included in the Freeze Frame and/or Failure Records data can help
determine how many miles since the DTC set. The Fail Counter and Pass
Counter can also help determine how many ignition cycles the diagnostic
reported a pass and/or a fail. Operate the vehicle within the same
freeze frame conditions (RPM, load, vehicle speed, temperature etc.)
that you observed. This will isolate when the DTC failed. For an intermittent
condition, refer to
Symptoms
.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Engine Overheating in Engine Cooling. |
