The P20D3: Exhaust Aftertreatment Fuel Injector ‘B’ Control Circuit Low indicates that the voltage in the control circuit for fuel injector ‘B’ is lower than expected. This could lead to injector malfunctions, causing improper fuel injection and potentially impacting emissions control. The issue could be related to faulty wiring, a malfunctioning injector, or a problem with the control module.
P20D3 – Quick Overview
Code | Information |
---|---|
Meaning | P20D3: Exhaust Aftertreatment Fuel Injector ‘B’ Control Circuit Low |
Is it serious? | Yes, this can lead to improper fuel injection, affecting emissions and vehicle performance. |
Possible causes | – Low voltage in the fuel injector ‘B’ control circuit – Faulty fuel injector ‘B’ – Faulty control module |
How to diagnose? | – Measure voltage in the injector control circuit – Test the fuel injector ‘B’ – Check the control module functionality |
P20D3 Meaning
The P20D3 fault code signals that there is a low voltage condition in the control circuit for fuel injector ‘B’. This may cause the injector to underperform or fail, leading to ineffective fuel injection in the exhaust aftertreatment system. Possible causes include wiring issues, a malfunctioning injector, or a fault in the control module.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Codes | Use an OBD-II scanner to check for additional codes that may provide more insight into the low voltage condition. | OBD-II Scanner |
Measure Voltage in the Injector Control Circuit | Use a multimeter to measure the voltage in the control circuit for fuel injector ‘B’ and ensure it is within manufacturer specifications. | Multimeter |
Test Fuel Injector ‘B’ | Use a diagnostic tool to test the functionality of fuel injector ‘B’ and ensure it is not being affected by the low voltage. | Multimeter, Diagnostic Tool |
Inspect the Control Module | Verify that the control module is functioning properly and is not causing the low voltage condition. | Diagnostic Tool |
Repair or Replace Wiring/Injector | If low voltage is detected, inspect wiring for faults, shorts, or disconnections, and repair or replace the injector as necessary. | Wiring Kit, Replacement Injector |
Clear the Code and Test Drive | After completing repairs, clear the code using an OBD-II scanner and test drive the vehicle to confirm that the issue is resolved. | OBD-II Scanner, Vehicle Manual |
Recheck for Codes | After the test drive, rescan the vehicle to ensure the P20D3 code does not return. | OBD-II Scanner |

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