For 1990-2009 cars only
Circuit Description
The PCM uses the ECT sensor to monitor the engine for an over temperature condition. This condition occurs when the coolant temperature is above 132°C (270°F). When an over temperature condition is present, DTC P1258 will set. The PCM will alternately disable 4 injectors. By alternately disabling 4 injectors, the PCM is able to reduce the temperature of the coolant.
Conditions for Running the DTC
| • | DTCs P0117, P0118, P1114, and P1115 are not active. |
| • | The engine is running. |
Conditions for Setting the DTC
| • | The engine coolant temperature is above 132°C (270°F). |
| • | The condition is present for more than 10 seconds. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator Lamp (MIL) during the first trip in which the diagnostic test has been run and failed. |
| • | The PCM will signal the IPC to turn ON the Service Engine Soon indicator. |
| • | The PCM will alternately disable two groups of four cylinders by turning OFF the fuel injectors. |
| • | The PCM will store conditions which were present when the DTC set as Freeze Frame and File Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF after three consecutive trips that the diagnostic has been run and passed. |
| • | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool Clear DTC Information function. |
Step | Action | Yes | No |
|---|---|---|---|
1 | Was the Diagnostic System Check for Engine Cooling performed? | Go to Step 2 | |
2 | Check the engine cooling fan for proper operation. Does the engine cooling fan operative properly? | Go to Engine Overheating |
