Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is having trouble reading the temperature of a special fluid that helps reduce pollution from the exhaust. It's like when a thermometer isn't working right and you can't tell if it's hot or cold outside.
The P2043 code is triggered when the Engine Control Module (ECM) detects a problem with the range or performance of the reductant temperature sensor circuit.
The reductant temperature sensor is part of the Selective Catalytic Reduction (SCR) system, which reduces emissions by injecting a urea-based fluid into the exhaust. The sensor measures the temperature of this fluid to ensure optimal performance. A P2043 code indicates that the sensor is not providing readings within the expected range, which may affect the SCR system's efficiency.
• Check Engine Light illuminated
• Possible reduction in fuel efficiency
• Increased emissions
• Potential for vehicle to enter limp mode
• Faulty reductant temperature sensor
• Wiring issues such as open or short circuits
• Poor electrical connection at the sensor
• Faulty ECM
Reductant: A fluid, typically urea-based, used in the SCR system to reduce emissions.
SCR: Selective Catalytic Reduction, a technology used to reduce vehicle emissions.
• Use an OBD-II scanner to confirm the code.
• Visually inspect the wiring and connectors for damage.
• Test the reductant temperature sensor for proper operation.
• Check for any additional trouble codes that may be related.
• Replace the reductant temperature sensor if faulty.
• Repair or replace damaged wiring or connectors.
• Clear the code and test drive to ensure the issue is resolved.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools (screwdrivers, pliers)
$150 - $400
Moderate
• Ford F-250
• Chevrolet Silverado
• Ram 2500
• Regular maintenance and inspection of the SCR system
• Use high-quality reductant fluid
• Ensure proper electrical connections and wiring integrity
Sensor Issue
• Have the vehicle inspected by a professional mechanic.
• Avoid ignoring the Check Engine Light, as it may lead to further issues.
• Consider regular vehicle diagnostics to catch issues early.
Check with the vehicle manufacturer for warranty coverage on emissions-related components.
The P2043 code has been more common in diesel vehicles equipped with SCR systems since stricter emissions standards were implemented.
Moderate – Addressing this issue promptly can prevent further emissions-related problems.
Operating a vehicle with a malfunctioning emissions system may violate environmental regulations and contribute to pollution.
• Engine running
• Vehicle at operating temperature
The reductant temperature sensor is typically located near the reductant tank or along the reductant line in the exhaust system.
Q: Can I drive with a P2043 code?
A: While the vehicle may still be drivable, it's best to address the issue to avoid increased emissions and potential engine performance problems.
Q: How does the reductant system help reduce emissions?
A: The system injects a urea-based fluid into the exhaust, which helps convert harmful nitrogen oxides into harmless nitrogen and water.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.