Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the part of the car that helps reduce pollution. It's like a squirt gun that helps clean the car's exhaust, but it's not working right now.
The P20CD code indicates that the control circuit for the exhaust aftertreatment fuel injector 'A' is reading a low voltage or is not functioning as expected.
The exhaust aftertreatment system uses a fuel injector to introduce additional fuel into the exhaust stream to help reduce emissions. The 'A' injector's control circuit is monitored by the engine control module (ECM), and if the voltage is lower than expected, the P20CD code is triggered.
• Check Engine Light is on
• Reduced engine performance
• Increased emissions
• Faulty exhaust aftertreatment fuel injector
• Open or shorted wiring in the injector circuit
• Faulty ECM or PCM
ECM: Engine Control Module
PCM: Powertrain Control Module
• Use an OBD-II scanner to confirm the code
• Inspect the wiring and connectors for damage
• Test the fuel injector for proper operation
• Repair or replace damaged wiring or connectors
• Replace the faulty fuel injector
• Reprogram or replace the ECM/PCM if necessary
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Ford F-250
• Chevrolet Silverado
• Ram 2500
• Regular maintenance of the exhaust system
• Use high-quality fuel
• Check for recalls related to emissions
Sensor Issue
• Do not ignore the Check Engine Light
• Get the vehicle inspected by a professional
• Avoid driving extensively until repaired
Check with the manufacturer for emissions-related warranty coverage.
This code has become more common with the increased use of aftertreatment systems in diesel engines.
Moderate – It should be addressed soon to prevent increased emissions and potential damage.
Ignoring emissions-related issues can lead to fines and increased environmental impact.
• Engine at operating temperature
• Vehicle in a safe environment for testing
The exhaust aftertreatment fuel injector is typically located near the exhaust manifold or catalytic converter.
Q: Can I drive with a P20CD code?
A: It's not recommended to drive for long periods with this code, as it can lead to increased emissions and potential engine damage.
Q: How can I reset the P20CD code?
A: The code can be reset with an OBD-II scanner, but it's important to fix the underlying issue first.
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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.
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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.
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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.