P246E – Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 4

Reinier

By Reinier (Contact Me)
Last Updated 2021-12-08
Automobile Repair Shop Owner

CodeFault LocationProbable Cause
P246E Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 4
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What Does Code P246E Mean?

OBD II fault code P246E is a generic code that is defined as, “Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 4”, and is set when the PCM (Powertrain Control Module) detects a failure, malfunction, or defect in an electrical circuit that is associated with the exhaust gas temperature sensor that is labeled #4 on bank 1. Bank 1 refers to the bank of cylinders on V-type engines that contains cylinder #1.

As their name suggests, exhaust gas temperature sensors measure the temperature of the exhaust gas as it passes through the exhaust system. Although exhaust gas temperature sensors are not yet in widespread use, on some applications, the exhaust gas temperature is measured at only one point in the exhaust system, while in many other applications, the exhaust gas temperature is measured at multiple points, and for various reasons.

For instance, on small-displacement gasoline engines with forced induction, high boost pressures over extended periods can raise the exhaust gas temperatures to potentially damaging levels. Thus, when the exhaust gas temperature sensor registers a maximum allowable temperature threshold, it relays this information to the PCM, which will then reduce the boost pressure to lower the exhaust gas temperature.

On diesel engines, exhaust gas temperature sensors are often used to monitor the temperature of the exhaust gas on either side of diesel particulate filters and catalytic converters. In the case of diesel particulate filters, the temperature of the exhaust gas is a fairly good indicator of the soot load in the filter, so when the temperature of the exhaust gas reaches a predefined threshold, the PCM will initiate a process that regenerates the diesel particulate filter to restore its ability to capture soot particles.

In terms of operating principles, exhaust gas temperature sensors are simple thermistors whose electrical resistance changes in response to changes in temperature. The PCM supplies the sensor with a 5-volt reference voltage, and the PCM interprets the changes in the current that flows through the sensor and back to it via a dedicated signal circuit as changes in temperature.

However, it is important to note that while all exhaust gas temperature sensors are thermistors, there are two different sensor designs that work in opposite ways. One design has a positive temperature coefficient, meaning that its electrical resistance increases with rising temperature. The other design has a negative temperature coefficient, meaning that its electrical resistance decreases as its temperature rises.

Either way, the PCM will continually convert an exhaust temperature sensors’ electrical resistance to an exhaust gas temperature while the engine is running, and the PCM will take appropriate action to reduce the exhaust gas’ temperature based on this calculated value. Nonetheless, if a failure, malfunction, or defect occurs that affects the operation of the sensor or the quality of its signals, the PCM will recognize that it cannot control the exhaust gas’ temperature effectively, and it will set a trouble code and illuminate a warning light as a result.

Where is the P246E sensor located?

This diagram shows the locations (circled) of the exhaust gas temperature sensors on either side of a catalytic converter.

Note, though, that apart from temperature sensors, the exhaust systems of many late-model vehicles can contain as many as a dozen or more other sensors, which means that testing or replacing the wrong sensor(s) is an easy mistake to make. Therefore, we strongly recommend that you consult reliable service/repair information for the affected vehicle to locate and identify the exhaust gas temperature sensor(s) correctly.

What are the common causes of code P246E?

The most common causes of code P246E are largely similar across all applications, and could include one or more of the following-

  • Defective or malfunctioning exhaust gas temperature sensor
  • Exposure to excessively high exhaust gas temperatures i.e., temperatures over 1 6000F
  • Damaged, burnt, shorted, corroded, or disconnected wiring and/electrical connectors
  • Contamination of the sensing element by oil, engine coolant, or silicone-based additives in oil or fuel
  • The use of substandard aftermarket sensors

What are the symptoms of code P246E?

NOTE: It is important to note that failures of exhaust gas temperature sensors with positive temperature coefficients are often misdiagnosed as DPF failures. This is because a sensor with a positive temperature coefficient will continue to function even after suffering a severe failure, which causes the sensor to relay incorrect signals to the PCM, which in its turn, may prevent the PCM from initiating DPF regeneration procedures.

Nonetheless, some common symptoms of code P246E could include one or more of the flowing-

  • Stored trouble code and an illuminated warning light
  • In some cases, multiple additional EGR, DPF, and or SCR (Selective Catalytic Reduction) related codes may be present along with code P246E
  • Fuel consumption may increase noticeably
  • Diesel engines may experience varying degrees of power loss
  • In some cases, multiple unnecessary DPF regenerations may occur during a single trip, which will have serious negative effects on fuel consumption for some vehicles
  • Excessively high exhaust gas temperatures can cause the failure of catalytic converters, DPF devices, mufflers, and other sensors in the exhaust system
  • The vehicle may fail an emissions test

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