P2043 – Reductant Tank Temperature Sensor Circuit Low

What is OBD-II Code P2043?

P2043 is a diagnostic trouble code (DTC) for "Reductant Temperature Sensor Circuit Range/Performance". This code indicates that the powertrain control module (PCM) has detected an abnormal voltage level in the reductant temperature sensor circuit.

Urgency and Severity

A stored code P2043 should be considered severe and addressed as quickly as possible. Continuing to drive with this code could disable the selective catalytic reduction (SCR) system and potentially cause catalyst damage if the underlying issue is not resolved promptly. It's recommended to diagnose and repair this code as soon as possible, but since it's unlikely to cause immediate drivability issues, you can drive cautiously to a repair shop.

Applicability

P2043 is a generic powertrain code that applies to many OBD-II vehicles (1996-newer), including vehicles from Mercedes, Sprinter, Ford, GMC, Chevrolet, etc. The exact repair steps may vary depending on the year, make, model, and powertrain configuration.

System and Parts Involved

This code is specific to vehicles with clean diesel engines that use a selective catalytic reduction (SCR) system to reduce NOx emissions. The main components involved are:

• Reductant/diesel exhaust fluid (DEF) tank and temperature sensor
• DEF supply pump
• SCR catalyst
• PCM or SCR control module

The reductant temperature sensor measures the DEF temperature and sends a signal to the PCM. The PCM uses this input to precisely control DEF injection timing and quantity in order to optimize the SCR system performance and emissions reduction.

Causes and Diagnosis

Possible causes for code P2043 include:

• Faulty reductant temperature sensor
• Damaged wiring or connectors related to the sensor
• Exhaust leaks upstream of the sensor
• Improper DEF fluid
• Faulty PCM/SCR controller

To diagnose, a technician would:

1. Scan for codes and document freeze frame data.
2. Visually inspect the DEF tank, sensor, wiring and connectors.
3. Test the reductant temperature sensor and compare to specs.
4. If the sensor tests okay, use a DVOM to check the sensor signal and ground circuits for opens/shorts.
5. Smoke test the exhaust for any leaks.
6. Check DEF quality and level.
7. Test PCM/SCR controller if no other causes are found.

Repairs and Costs

Repairs for a P2043 code may involve:

• Replacing the reductant temperature sensor: $150-300 (€125-250)
• Repairing damaged wiring or connectors: $50-150 (€40-125)
• Fixing an exhaust leak: $100-600 (€80-500) depending on location and severity
• Replacing contaminated DEF fluid: $20-80 (€15-65) plus labor
• Reflashing or replacing the PCM: $500-1500 (€400-1250)

Prevention

To prevent P2043 and related issues:

• Maintain proper DEF levels and only use high quality diesel exhaust fluid
• Address any exhaust leaks promptly
• Have the SCR system inspected if you suspect any issues
• Avoid modifying or tampering with emissions control components

Associated Codes

Other codes commonly associated with P2043 include:

• P2042 – Reductant Temperature Sensor Circuit Low
• P2044 – Reductant Temperature Sensor Circuit High
• P2045 – Reductant Temperature Sensor Circuit Intermittent
• P2056 – Reductant Injector Performance

I hope this in-depth article on trouble code P2043 is helpful for your blog readers. Let me know if you need any other information!

Frequently Asked Questions About P2043

What does the P2043 code mean?

P2043 is a diagnostic trouble code (DTC) for “Reductant Temperature Sensor Circuit Range/Performance”. It indicates that the powertrain control module (PCM) has detected an abnormal voltage level in the reductant temperature sensor circuit.

What are the symptoms of a P2043 code?

Symptoms may include:

• Illuminated check engine light
• Reduced engine power
• Increased fuel consumption
• Rough running or misfires
• Difficulty starting the engine

What causes a P2043 code?

Possible causes include:

• Faulty reductant temperature sensor
• Damaged wiring or connectors
• Exhaust leaks upstream of the sensor
• Improper diesel exhaust fluid (DEF)
• Faulty PCM or SCR controller

How serious is a P2043 code?

A P2043 code should be considered severe. Continuing to drive with this code could disable the SCR system and potentially cause catalyst damage if not resolved promptly.

Can I drive with a P2043 code?

It’s recommended to diagnose and repair this code as soon as possible. However, since it’s unlikely to cause immediate drivability issues, you can drive cautiously to a repair shop.

What vehicles can get a P2043 code?

P2043 is a generic code that applies to many OBD-II vehicles (1996-newer) with diesel engines and SCR systems, including Mercedes, Sprinter, Ford, GMC, Chevrolet, etc.

What systems are involved with P2043?

This code relates to the selective catalytic reduction (SCR) system used to reduce NOx emissions in diesel vehicles. The main components are the DEF tank, supply pump, reductant temperature sensor, SCR catalyst, and PCM.

How does the reductant temperature sensor work?

The reductant temperature sensor measures the DEF temperature and sends a signal to the PCM. The PCM uses this input to control DEF injection timing and quantity to optimize SCR performance.

What are the diagnostic steps for P2043?

Diagnosis involves:

1. Scanning for codes and freeze frame data
2. Visual inspection of DEF system components
3. Testing the reductant temperature sensor
4. Checking sensor signal and ground circuits
5. Performing an exhaust leak test
6. Verifying DEF quality and level
7. Testing the PCM/SCR controller

How much does it cost to fix a P2043 code?

Repair costs can range from $150-300 to replace the reductant temperature sensor, up to $1500 or more if the PCM needs replacing. Total costs depend on the root cause.

Can a P2043 code clear itself?

P2043 will not clear itself and requires diagnosis and repair of the underlying issue. The code may go dormant if the fault is intermittent but will return.

How often should the reductant temperature sensor be replaced?

There is no specific replacement interval. The sensor should be replaced if it fails diagnostics when a P2043 code is set.

What happens if I ignore a P2043 code?

Ignoring a P2043 code could result in disabling of the SCR system, increased emissions, reduced fuel economy, and potential catalyst damage.

How do you prevent a P2043 code?

Proper maintenance of the DEF system, using high-quality DEF, and promptly repairing any exhaust leaks or sensor issues can help prevent a P2043 code.

Are there any recalls or TSBs related to P2043?

Recall and TSB information varies by year, make and model. Check with your dealer or the NHTSA website for any that may apply to your specific vehicle.

Can a weak battery cause a P2043 code?

While a weak battery alone is unlikely to cause a P2043 code, low system voltage could potentially affect sensor readings and trigger this code in some cases.

Will disconnecting the battery clear a P2043 code?

Disconnecting the battery may temporarily clear the code but it will return if the underlying problem is not fixed. Proper diagnosis and repair is required.

What other codes may be present with P2043?

Related codes that may appear with P2043 include P2042 (low input), P2044 (high input), P2045 (intermittent signal), and P2056 (reductant injector performance).

Can a P2043 code affect other components?

Yes, a faulty reductant temperature sensor triggering a P2043 code can cause issues with DEF injection, leading to SCR and catalyst problems if unaddressed.

Is it safe to use DEF additives with a P2043 code?

No, it is not recommended to use any DEF additives, as this may further damage the SCR system. Only use DEF fluid that meets ISO 22241 specifications.