The P246A trouble code reads an intermittent signal in the exhaust gas temperature sensor circuit (Bank 2 Sensor 3). Often, in programs working with an OBD-2 scanner, the name may have the English spelling “Exhaust Gas Temperature (EGT) Sensor Circuit Intermittent (Bank 2 Sensor 3)”.
P246A datasheet and explanation
This Diagnostic Trouble Code (DTC) is a generic transmission code. The P246A code is considered a generic code as it applies to all makes and models of vehicles. Although the specific repair steps may differ slightly depending on the model.
EGR is responsible for recirculating the exhaust gas. It is part of the vehicle’s exhaust system. It is used to reduce temperature, combustion pressure, and to control nitrogen oxides.
The function of the exhaust gas temperature sensor is to monitor the temperature in the recirculation system. And adjust the flow accordingly with the EGR valve. Which is built on the basis of a conventional temperature-sensitive resistor type sensor.
The higher the temperature of the exhaust gases, the less resistance to ground, which results in a higher voltage. Conversely, the lower the temperature, the greater the resistance, which leads to a decrease in voltage.
If the PCM detects a change in voltage, the computer changes the valve timing or fuel ratio. To keep the temperature within the allowable range inside the transmitter.
In diesel engines, the reading from the exhaust gas temperature sensor is used to determine the regeneration time of the particulate filter.
When the powertrain control module (PCM) detects an intermittent signal on the exhaust gas temperature sensor circuit (Bank 2 Sensor 3). DTC P246A will be stored and an error message will appear on the control panel.
The primary driver symptom of a P246A code is a MIL (Malfunction Indicator Light) illuminated. It is also called Check engine or simply “check is on”.
They can also manifest as:
- The control lamp “Check engine” on the control panel will light up (the code will be written into memory as a malfunction).
- Increased engine noise, ringing and rattling may also be present.
- Increased emissions of harmful substances in the exhaust.
- Excessive exhaust odor.
- There may be other symptoms as well.
From a technical point of view, error P246A is not considered serious, but from an environmental point of view, emissions of harmful substances are greatly increased. However, it is necessary to fix the problem, because any malfunction can lead to more serious consequences.
Reasons for the error
A P246A code could indicate one or more of the following problems have occurred:
- Exhaust gas temperature sensor defective.
- Short circuit to ground or inside the exhaust gas temperature sensor.
- Leakage in the gasket of the exhaust gas recirculation temperature sensor.
- Cracked or leaking exhaust pipe in which the sensor is installed.
- The wiring harness or sensor may be damaged.
- The wires are open or short.
- Damaged connector.
- Aftermarket installation of an exhaust system that causes pressure problems.
- Intermittent communication with the control unit.
- Sometimes the cause is a faulty ECM.
How to Repair or Reset DTC P246A
Some suggested steps to troubleshoot and fix the P246A error code:
- Clear the error codes and test drive the vehicle to see if the P246A code appears again.
- Visually inspect the exhaust gas temperature sensor and all associated circuits, especially where they come into contact with hot components.
- Check connectors for looseness and corrosion.
- Inspect the wires for damage that could cause a short circuit.
- Check the resistance of the exhaust gas temperature sensor with an ohmmeter.
- Test the exhaust gas temperature sensor.
- Check for leaks in the system.
- Test the ECM and communication with it.
Diagnostics and problem solving
First, you need to read all stored data and error codes with a scanner. Then clear the error codes and test drive the vehicle. To find out if the P246A code appears again.
After that, visually inspect the exhaust gas temperature sensor, you should pay attention to the exhaust gas leaks. Also check the sensor itself and the wiring harness that fit it. High temperatures can damage plastic and rubber wires, so check them carefully.
Black soot may indicate an exhaust leak, so carefully inspect the connections.
Checking the sensor and EGR system
Many EGR problems are caused by the accumulation of soot in the exhaust. Therefore, it can be helpful to clean the EGR system, or at least the temperature sensor.
After removing the sensor, use a carburetor cleaner or similar product to effectively saturate the soot. Use a wire brush to remove excess soot from accumulated areas. When reinstalling a clean sensor, be sure to apply anti-seize compound to the threads to prevent galling.
To test the sensor, use a hair dryer or heat gun to heat while observing an ohmmeter. The resistance should drop when the sensor heats up and increase when it cools down, if this does not happen, replace it.
If the sensor itself is faulty, a 2.2 ohm resistor can be installed as a temporary measure to clear the P246A code. Simply remove the EGT sensor and connect the resistor to the motor side electrical connector, insulate it, and the computer will verify that the EGT is working properly.
On what cars does this problem occur more often?
The problem with the P246A code can occur on different machines, but there are always statistics on which brands this error is more common. Here is a list of some of them:
- BMW (BMW X5)
- Toyota (Toyota Rav4)
Other errors can sometimes be found with DTC P246A. The most common are the following: P2466, P2467, P2468, P2469.