P2043 OBD-II Trouble Code: Reductant Temperature Sensor Circuit Range/Performance

P2043 code definition

Reductant Temperature Sensor Circuit Range/Performance

What the P2043 code means

This code indicates that the powertrain control module has detected a malfunction with the reductant injector air pressure/temperature sensor. This sensor is used to reduce gases or emissions that come from the exhaust.

What are the causes of the P2043 code?

Some potential causes of this trouble code may include:

• Wiring or connectors that are associated with the exhaust temperature sensor may be damaged.

• The exhaust temperature sensor is faulty.

• An aftermarket exhaust system that does not conform to the manufacturer’s specifications may be installed.

• The powertrain control module may be faulty.

• A large exhaust leak upstream of the exhaust temperature sensor may exist.

What are the symptoms of the P2043 code?

Symptoms that the driver with this trouble code may experience would be black smoke coming from the exhaust upon startup and a Check Engine Light that is illuminated.

How does a mechanic diagnose the P2043 code?

A mechanic may begin diagnosing this trouble code by getting under the vehicle and visually inspecting the exhaust system. Part of this inspection would include locating the exhaust temperature sensor. Once this sensor has been located, the mechanic would then make sure that the wiring and connectors that go to it are in good condition. If so, the mechanic would then test the sensor to ensure it is working properly using the manufacturer’s recommended procedure.

Following this test would be a smoke test on the exhaust to see if any exhaust leaks exist that are not obvious. If no issues were found during this test, the powertrain control module would be tested for proper function. If any issues are found during this procedure, they would be relayed over to the customer to make a repair decision.

Common mistakes when diagnosing the P2043 code

A common mistake that can be made when diagnosing this trouble code would be replacing an oxygen sensor instead of replacing the exhaust temperature sensor. These are two separate sensors so be sure to locate the correct sensor for testing and replacement.

How serious is the P2043 code?

This trouble code is moderately serious. This code being stored for a long period of time can affect the way the engine runs. The engine will not be able to breathe efficiently with this code stored in the powertrain control module. It is recommended to have this trouble code diagnosed and repaired as soon as possible. However, since this trouble code is unlikely to cause a drivability issue, it can be put on the back burner for a short time.

What repairs can fix the P2043 code?

Repairs that can fix this trouble code would include:

• Repairing or replacing wiring or connectors that are associated with the exhaust temperature sensor

• Replacing the exhaust temperature sensor

• Repairing an exhaust leak

• Replacing an aftermarket exhaust system with the factory exhaust system

• Replacing the powertrain control module

Additional comments regarding the P2043 code

This trouble code may be associated with other trouble codes such as P2042, P2044, P2045, and P2056, as they are all related to the reductant temperature sensor. It is important to consider what all the trouble codes together could potentially mean. Multiple trouble codes can often assist in the diagnostic process due to the fact that codes are only set under certain parameters. If more codes exist, find out which parameter all the codes have in common and this will lead you to the faulty part.

Need help with a P2043 code?

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