P1258 is an OBD-II Code that refers to Engine Coolant Overtemperature Protection Mode Active. To know more about this error code, keep reading.
What is a P1258 error code?
The powertrain control module (PCM) uses the engine coolant temperature (ECT) sensor to monitor the engine for an over-temperature condition. This condition occurs when the coolant temperature is above 128 C (262 F). When an over-temperature condition is present, DTC P1258 will set.
The PCM will disable two groups of cylinders by turning OFF the fuel injectors. By switching between the two groups of cylinders, the PCM is able to reduce the temperature of the coolant. ECM (Engine Control Module) gets a P1258 code when the PCM (Powertrain Control Module) tells it that the engine is too hot.
When this happens, the ECM will turn off the primary ignition system to keep more damage from happening. When the engine coolant gets too hot, the P1258 code is set because the protection mode is on.
It’s never a good thing when an engine gets too hot. If you catch the problem quickly, you can avoid having to deal with a major engine repair. If you know what’s in the next guide, you’ll be able to make the right choice when one of the following symptoms shows up.
What causes engine overheating?
There are a lot of things that can cause an engine to get too hot. One of the most common reasons is that the cooling system doesn’t have enough coolant. If this level is low, the heat inside the engine will stay, and as the temperature goes up, steam will be made.
Most of the time, low coolant is caused by a leak in the system or the engine. A mechanical problem, like a thermostat that won’t open, will stop coolant from getting into the radiator. This will also cause the car to overheat. A broken head gasket or a cooling fan that won’t turn on are two other mechanical problems that can happen.
If you run an engine while it is too hot, the pistons will expand and get stuck in the cylinder bore, and the engine block and cylinder heads will crack. If you think the engine is overheating, don’t try to check the coolant level or open the cooling system because it is under pressure and hot coolant can burn you if you aren’t careful. Before checking for a problem, you should always let the engine cool down.
P1258 error code: Causes
- Low level of engine coolant or a radiator that is empty
- Thermostat that leaks or won’t stay open
- Plugged radiator
- Engine Coolant Temperature Sensor Does Not Work
- Bad connection with the engine coolant temperature sensor
- Bad Circuit
P1258 error code: Symptoms
- The engine’s warning light comes on.
- The engine gets too hot.
- The car stops running and won’t start in the end.
P1258 error code: Diagnosis
To figure out what a P1258 DTC code means, a mechanic would:
- Try to find codes.
- Check for leaks, level, and condition of the coolant.
- Make sure the thermostat works right.
- Check the parts of the cooling system.
- Look for blockages in the radiator and hoses.
Common mistakes while diagnosing a P1258 error code
Here are some of the most common mistakes a mechanic may make when trying to figure out what a P1258 code means:
- Not making sure there is enough coolant in the system.
- Not changing the thermostat if it is thought to be broken.
- Getting rid of the code without fully figuring out what it means.
- Not checking to see if the coolant temperature sensor circuit has any corrosion or loose connections.
- When you find intermittent problems, you have to replace parts that are not broken.
How bad could a P1258 error code be?
If you get a P1258 code, you should take it seriously because the problem will only get worse if you don’t fix it. If a car is overheating quickly, it could cause damage to the engine, like warped cylinder heads and blown head gaskets. The driver should stop as soon as it is safe to do so, turn off the engine, and call for help right away.
Cost of getting a P1258 code fix
It takes one hour of work to figure out what the P1258 code means. Auto repair rates depend on where you live, the make and model of your car, and even the kind of engine it has. Most shops charge between $75 and $150 per hour to fix a P1258 code.
What repairs can fix the code?
The following are solutions that may fix this problem:
- Visually inspect for low coolant levels or an empty radiator
- Replace the thermostat
- Check the coolant temperature sensor for proper connection and operation
- Repair any leaks in the cooling system components
- Clean out any obstructions in the cooling system hoses
- Inspect wiring connections to connectors in the cooling system circuit. If needed, replace connectors that are corroded or faulty.