P2121Medium Severity
Supplemental Output Circuit Error / Component 2121
This diagnostic trouble code indicates a malfunction in the associated component circuit.
Common Symptoms of P2121
- MIL Illumination
- Reduced power
What Causes the P2121 Code?
- Wiring issue
- Component failure
How serious is the P2121 code?
Because this code has a medium severity level, it is highly recommended to address it promptly. Driving with an active P2121 fault can lead to secondary component failures and decreased fuel economy.
How do you definitively diagnose and fix P2121?
To accurately diagnose the P2121 fault code, you need the exact OEM wiring diagram and diagnostic test procedures for your specific vehicle. Create an Auto Fix Data account to instantly pull the factory diagrams for this fault.
Fix P2121 Now
Access the OEM repair manual and interactive wiring diagram to diagnose this exact code.
- Pin-to-pin wiring diagrams
- Component testing steps
- Technical Service Bulletins
- Identifix confirmed fixes
Related Fault Codes
P0001
Fuel and Air Metering System Malfunction (Circuit 0001)
P0002
Fuel and Air Metering System Malfunction (Circuit 0002)
P0003
Fuel and Air Metering System Malfunction (Circuit 0003)
P0004
Fuel and Air Metering System Malfunction (Circuit 0004)
P0005
Fuel and Air Metering System Malfunction (Circuit 0005)
P0006
Fuel and Air Metering System Malfunction (Circuit 0006)