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 there's a problem with the part of the car that helps clean the exhaust. It's like a squirt gun that sprays special liquid to clean the car's smoke, but the squirt gun isn't working right.
The code P20D3 indicates that the control circuit for the aftertreatment fuel injector B is operating at a low voltage, which means it might not be working properly.
The P20D3 code is triggered when the Engine Control Module (ECM) detects that the voltage in the control circuit for the exhaust aftertreatment fuel injector B is lower than expected. This injector is responsible for delivering a precise amount of fuel into the exhaust system to aid in reducing emissions.
• Check Engine Light is on
• Poor fuel efficiency
• Increased emissions
• Faulty exhaust aftertreatment fuel injector B
• Open or shorted wiring in the injector circuit
• Faulty ECM
ECM: Engine Control Module
OBD-II: On-Board Diagnostics II
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage.
• Test the voltage and continuity of the injector circuit.
• Repair or replace damaged wiring or connectors.
• Replace the exhaust aftertreatment fuel injector B.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Chevrolet Silverado
• GMC Sierra
• Ford F-Series
• Regular maintenance of the exhaust system
• Using high-quality fuel
• Regularly checking for wiring issues
Sensor Issue
• Do not ignore the Check Engine Light.
• Seek professional diagnostic services if unsure.
• Monitor vehicle performance for any changes.
Check with the vehicle manufacturer for specific warranty coverage on emissions-related components.
This code has been associated with issues in vehicles with advanced emission control systems, particularly diesel engines.
Moderate – Should be addressed soon to prevent further emissions-related issues.
Driving with this issue may result in failing emissions tests and increased pollution.
• Engine running
• Vehicle at operating temperature
The exhaust aftertreatment fuel injector is typically located near the exhaust system, often around the diesel particulate filter or catalytic converter.
Q: Can I drive with a P20D3 code?
A: It's not recommended as it can lead to increased emissions and potential damage to the exhaust system.
Q: How do I reset the Check Engine Light after fixing the issue?
A: Use an OBD-II scanner to clear the code, or disconnect the battery for a few minutes.
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.
Fitment Required · Vehicle-fitment part
Relevant when catalyst-efficiency or emissions faults persist after proper diagnosis.
Catalyst-efficiency faults sometimes point toward converter problems after proper testing.
Catalytic converters are highly vehicle-specific and should not be purchased by code alone.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.