DTC P1258 LFA
Diagnostic Instructions
DTC Descriptor
DTC P1258: Engine Coolant Over temperature - Protection Mode Active
Circuit/System Description
The engine control module (ECM) uses the engine coolant temperature (ECT) sensor to monitor the engine for an over-termperature condition. This condition occurs when the coolant temperature is above a calibrated value for a calibrated length of time. The
ECM will disable half of the cylinders by turning OFF the fuel injectors. By disabling half of cylinders, the ECM is able to reduce the temperature of the coolant.
Conditions for Running the DTC
• | DTC P0117 or P0118 are not set. |
Conditions for Setting the DTC
Coolant temperature more than 132°C (270°F) for greater than 10 seconds.
Action Taken When the DTC Sets
• | DTC P1258 is a Type A DTC. |
• | The engine will operate in the Overheated Engine Protection Operating Mode. |
• | The engine coolant temperature indicator lamp, if equipped, will illuminate. |
• | The driver information center (DIC), if equipped, may display a message. |
Conditions for Clearing the DTC
DTC P1258 is a Type A DTC.
Reference Information
Description and Operation
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References
for scan tool information
Circuit/System Verification
Important: If DTC P1482 is set, diagnose that DTC first.
- Ignition OFF, open the hood to disable the Auto-Stop function. Refer to
Hybrid Modes of Operation Description
.
- Ignition ON, verify the scan tool hood position parameter displays Open.
- Observe the engine coolant level. The engine coolant level should be within operating range. Refer to Capacities - Approximate Fluid, and Engine Coolant in the Owner's Manual.
- Ensure that the vehicle has the correct engine coolant, with correct concentration, and is not old, contaminated or contains additives. Refer to Recommended Fluids and Lubricants in the Owner's Manual.
- Inspect the cooling system for the following:
• | Kinked or pinched hoses, especially at the radiator |
• | Loose, missing, or damaged radiator air seals or deflectors |
Important: A small delay occurs before the ECM changes the cooling fan speed.
- Command the cooling fan speed from 0% to 100% with a scan tool.
Circuit/System Testing
- Ignition OFF, open the hood to disable the Auto-Stop function. Refer to
Hybrid Modes of Operation Description
.
- Ignition ON, verify the scan tool hood position parameter displays Open.
- Test the thermostat for correct operation. Refer to
Thermostat Diagnosis
.
- Test the engine cooling system for overheating. Refer to
Engine Overheating
.
- Inspect the water pump and coolant flow for correct operation. Refer to
Water Pump Replacement
.
- Inspect the engine for worn/leaking/cracked cylinder heads and engine block. Refer to
Coolant in Combustion Chamber
and
Coolant in Engine Oil
.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
DTC P1258 w/o LFA
Diagnostic Instructions
DTC Descriptor
DTC P1258: Engine Coolant Overtemperature - Protection Mode Active
Circuit/System Description
The engine control module (ECM) uses the engine coolant temperature (ECT) sensor to monitor the engine for an over-termperature condition. This condition occurs when the coolant temperature is above a calibrated value for a calibrated length of time. The
ECM will disable half of the cylinders by turning OFF the fuel injectors. By disabling half of the cylinders, the ECM is able to reduce the temperature of the coolant.
Conditions for Running the DTC
• | DTC P0117 or P0118, are not set. |
Conditions for Setting the DTC
Coolant temperature more than 130°C (266°F) for more than 10 seconds.
Action Taken When the DTC Sets
• | DTC P1258 is a Type A DTC. |
• | The engine will operate in the Overheated Engine Protection Operating Mode. |
• | The engine coolant temperature indicator lamp, if equipped, will illuminate. |
• | The driver information center (DIC), if equipped, may display a message. |
Conditions for Clearing the DTC
DTC P1258 is a Type A DTC.
Reference Information
Description and Operation
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
If DTCs P0480 or P0481 are set, diagnose those DTCs first.
- Observe the engine coolant level. The engine coolant level should be within operating range. Refer to Capacities - Approximate Fluid, and Engine Coolant in the Owner's Manual.
- Ensure that the vehicle has the correct engine coolant, with correct concentration, and is not old, contaminated or contains additives. Refer to Recommended Fluids and Lubricants in the Owner's Manual.
- Inspect the cooling system for the following:
• | Kinked or pinched hoses, especially at the radiator |
• | Loose, missing, or damaged radiator air seals or deflectors |
Important: A small delay occurs before the ECM changes the cooling fan speed.
- Command the cooling fans in both low and high speed.
Circuit/System Testing
- Test the thermostat for correct operation. Refer to
Thermostat Diagnosis .
- Test the engine cooling system for overheating. Refer to
Engine Overheating .
- Inspect the water pump and coolant flow for correct operation. Refer to
Water Pump Replacement .
- Inspect the engine for worn/leaking/cracked cylinder heads and engine block. Refer to
Coolant in Combustion Chamber and
Coolant in Engine Oil .
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.