Fault code P0298 is called “Engine Oil Over Temperature Condition” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.
Technical description and explained code P0298
This Diagnostic Trouble Code (DTC) is a generic powertrain code. Error P0298 is considered a general code because it applies to all makes and models of vehicles. Although the specific repair steps may vary slightly depending on the model.
A stored error indicates that the powertrain control module (PCM) has detected an engine oil temperature that exceeds the allowable temperature. The conditions contributing to this stored code may be electrical or mechanical.
Some vehicles are equipped with a system that monitors the oil temperature, most commonly used on diesel engines. Engine oil temperature sensors are thermistors with a negative coefficient of resistance. Which reduce the resistance of the circuit as the oil temperature rises.
When the oil temperature rises and the sensor resistance decreases, the voltage in the circuit becomes higher. The PCM is programmed to recognize these sensor circuit voltage changes as different degrees of oil temperature.
In some cases, the engine oil temperature sensor also provides an electrical signal to the engine oil temperature gauge. This is displayed on the dashboard for the driver’s convenience.
If the PCM detects a voltage level in the engine oil temperature sensor circuit that does not match the programmed parameters. Then code P0298 will be stored in the memory and the malfunction indicator light may illuminate.
Symptoms of vehicle malfunctions
The main signal that an error P0298 has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.
It can also be warning signs such as:
- The “Check engine” control lamp on the control panel will light up (the code will be memorized as a fault).
- Engine cooling system codes may be present.
- Sometimes increased engine noise is present.
- Burning oil odor.
- Engine coolant leakage.
- Decreased engine power.
Error P0298 is quite serious, because when it occurs, it can cause problems with the engine and vehicle handling. The engine should not be operated until the conditions causing this code to persist are corrected.
Factors that can cause this error code
The error code P0298 can mean that one or more of the following problems have occurred:
- Faulty engine oil temperature sensor.
- Overheating due to engine cooling system condition.
- Broken or short circuit in wiring harness.
- Faulty wiring harness connector.
- Low oil level.
- Sometimes faulty PCM module is the cause.
How to fix or reset OBD-2 code P0298
Some suggested steps for troubleshooting and fix the error code P0298:
- Read all stored data and error codes with an OBD-II scan tool. To find out when and under what circumstances error P0298 appeared.
- Clear the error codes from the computer memory and test-drive the vehicle to find out if the malfunction appears again.
- If the error code appears again, visually inspect the electrical wires and connectors.
- Check the engine oil temperature sensor.
- Test the engine cooling system, and check the engine oil level.
- If there are no defects, check the PCM itself and its program part.
Diagnose and repair of problems
Before diagnosing code P0298, you must visually inspect the system wiring and connectors for damage. Also make sure the engine oil and coolant are level.
Overheating the engine is the primary cause of overheating, and coolant leakage can also be an issue. Other causes are a bad thermostat, a faulty cylinder head or gasket, and air flow problems.
Make sure the engine cooling system is full of coolant and that all fans are operating as intended. If the cooling system is low on fluid, look for leaks and repair them.
Check sensor and wiring
Connect the scan tool to the vehicle’s diagnostic connector and retrieve all the stored codes and stop frame data. Once you’ve recorded all the stored codes, delete them and test-drive to see if the P0298 error has reset.
If the error remains, you need to check the engine oil temperature sensor, as well as the associated circuits. Disconnect the engine oil temperature sensor connector and use a multimeter to check for a reference voltage signal and ground at the connector.
After checking the connector positively, check the sensor for resistance. If it does not meet specifications, it must be replaced.
If there is no reference voltage on the sensor connector, locate the corresponding circuit on the PCM connector and use a multimeter to check for a reference voltage. If there is a voltage reference on the PCM and no voltage reference on the oil temperature sensor, there is most likely a broken or shorted wire between the two.
If there is no reference voltage on the PCM connector, the control module is most likely defective or has a programming error.
On which vehicles does this problem occur most frequently
Fault code P0298 can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:
- Chevrolet
- Chrysler (200)
- Dodge
- Ford
- Jeep (Grand Cherokee)
- Nissan
- Subaru
- Suzuki
- Volkswagen
Fault code P0298 can sometimes be found with other errors. The most common are the following: P0195, P0196, P0197, P0198, P0199, P0200, P02FF.
