The P2046 code shows when there has been a malfunction in the reductant injector air temperature sensor circuit.
What the P2046 code implies
The reductant injector is component of the system that lowers the gas that is expelled through either the catalytic converter in gas engines, or the particulate filter in diesel engines. There are sensors in the exhaust system, used by the reductant injector to input voltage readings to the PCM. These readings permit the PCM to monitor the exhaust system operation, in particular the pressure and the temperature. If this code is stored, it implies that the PCM observed that the temperature for the system was not correct.
What are the causes of the P2046 code?
In most instances, this code is the result of corroded, burnt, or damaged wiring, connectors, or other electrical parts. However, the PCM may detect an problem if:
- The exhaust gas temperature sensor is shorted.
- The reductant temp sensor is faulty.
- The owner has mounted an aftermarket off-road system that decreases the backpressure.
- There is an exhaust leak.
What are the signs of the P2046 code?
The Check Engine light will come on, and the vehicle may expel heavy black smoke when accelerating.
How should a mechanic diagnose the P2046 code?
For this code to be diagnosed, the mechanic should first start by inspecting the electrical components, and repairing any that are damaged, corroded, loose, or shorted. In many situations, this will solve the issue behind the P2046 code. After performing this task, the code should be cleared from the PCM, and the system should be retested.
If the code shows up again, then the mechanic should continue with a visual inspection of the exhaust gas temperature sensors, as well as the related circuitry. A digital volt/ohmmeter may be required to compare the voltage reading with the manufacturer’s specifications. The mechanic should always clear the code and retest the system after each possible repair, to be sure that they’ve made the proper diagnosis. Once the faulty part is found, it should be repaired or replaced as necessary.
Common mistakes made when diagnosing the P2046 code
Very often, mistakes are made when this code is misdiagnosed for a different code entirely. Oxygen sensors are often changed instead of exhaust gas temperature sensors, for example, which does not solve the problem causing the P2046 code.
How serious is P2046 code?
While this code will not directly affect the drivability of the vehicle, it is still considered an important problem that should be dealt with immediately. Without the ability to properly check and control the exhaust system, the car will not pass an emissions test. Ignoring this problem could result in larger and more expensive repairs in the future.
What repairs can clear the P2046 code?
For the P2046 code to be repaired, the cause behind the P2046 code, the mechanic may:
- Change faulty electrical components.
- Change a shorted exhaust gas temperature sensor.
- Change a faulty reductant temp sensor.
- Fix an exhaust leak.