Fuel System Codes
5,039 OBD-II diagnostic trouble codes in this category.
Showing page 32 of 51 (5,039 codes total)
| Code | Description | Subsystem | Severity |
|---|---|---|---|
| P215A | Vehicle Speed - Wheel Speed Correlation | Fuel Injection | Medium |
| P215B | Vehicle Speed - Output Shaft Speed Correlation | Fuel Injection | Medium |
| P215C | Output Shaft Speed - Wheel Speed Correlation | Fuel Injection | Medium |
| P215D | Reductant Pump B Stuck On | Fuel Injection | Medium |
| P215E | Reductant Heater D Current Too Low | Fuel Injection | Medium |
| P215F | Reductant Heater D Current Too High | Fuel Injection | Medium |
| P216A | Fuel Injector Group E Supply Voltage Circuit/Open | Fuel Injection | Medium |
| P216B | Fuel Injector Group E Supply Voltage Circuit Low | Fuel Injection | Medium |
| P216C | Fuel Injector Group E Supply Voltage Circuit High | Fuel Injection | Medium |
| P216D | Fuel Injector Group F Supply Voltage Circuit/Open | Fuel Injection | Medium |
| P216E | Fuel Injector Group F Supply Voltage Circuit Low | Fuel Injection | Medium |
| P216F | Fuel Injector Group F Supply Voltage Circuit High | Fuel Injection | Medium |
| P2177 | System Too Lean Off Idle Bank 1 | Fuel Trim | Medium |
| P2178 | System Too Rich Off Idle Bank 1 | Fuel Trim | Medium |
| P2179 | System Too Lean Off Idle Bank 2 | Fuel Trim | Medium |
| P217A | Fuel Injector Group G Supply Voltage Circuit/Open | Fuel Injection | Medium |
| P217B | Fuel Injector Group G Supply Voltage Circuit Low | Fuel Injection | Medium |
| P217C | Fuel Injector Group G Supply Voltage Circuit High | Fuel Injection | Medium |
| P217D | Fuel Injector Group H Supply Voltage Circuit/Open | Fuel Injection | Medium |
| P217E | Fuel Injector Group H Supply Voltage Circuit Low | Fuel Injection | Medium |
| P217F | Fuel Injector Group H Supply Voltage Circuit High | Fuel Injection | Medium |
| P2180 | System Too Rich Off Idle Bank 2 | Fuel Trim | Medium |
| P2187 | System Too Lean at Idle (Bank 1) | Fuel Trim | Medium |
| P2188 | System Too Rich at Idle (Bank 1) | Fuel Trim | Medium |
| P2189 | System Too Lean at Idle Bank 2 | Fuel Trim | Medium |
| P218F | Reductant No Flow Detected | Fuel Injection | Medium |
| P2190 | System Too Rich at Idle Bank 2 | Fuel Trim | Medium |
| P2191 | System Too Lean at Higher Load Bank 1 | Fuel Trim | Medium |
| P2192 | System Too Rich at Higher Load Bank 1 | Fuel Trim | Medium |
| P2193 | System Too Lean at Higher Load Bank 2 | Fuel Trim | Medium |
| P2194 | System Too Rich at Higher Load Bank 2 | Fuel Trim | Medium |
| P219A | Bank 1 Air-Fuel Ratio Imbalance | Fuel Injection | Medium |
| P219B | Bank 2 Air-Fuel Ratio Imbalance | Fuel Injection | Medium |
| P219C | Cylinder 1 Air-Fuel Ratio Imbalance | Fuel Injection | Medium |
| P219D | Cylinder 2 Air-Fuel Ratio Imbalance | Fuel Injection | Medium |
| P219E | Cylinder 3 Air-Fuel Ratio Imbalance | Fuel Injection | Medium |
| P219F | Cylinder 4 Air-Fuel Ratio Imbalance | Fuel Injection | Medium |
| P21A0 | Cylinder 5 Air-Fuel Ratio Imbalance | Fuel Metering | Medium |
| P21A1 | Cylinder 6 Air-Fuel Ratio Imbalance | Fuel Metering | Medium |
| P21A2 | Cylinder 7 Air-Fuel Ratio Imbalance | Fuel Metering | Medium |
| P21A3 | Cylinder 8 Air-Fuel Ratio Imbalance | Fuel Metering | Medium |
| P21A4 | Cylinder 9 Air-Fuel Ratio Imbalance | Fuel Metering | Medium |
| P21A5 | Cylinder 10 Air-Fuel Ratio Imbalance | Fuel Metering | Medium |
| P21A6 | Cylinder 11 Air-Fuel Ratio Imbalance | Fuel Metering | Medium |
| P21A7 | Cylinder 12 Air-Fuel Ratio Imbalance | Fuel Metering | Medium |
| P21A8 | Reductant Level Sensor B Circuit | Fuel Metering | Medium |
| P21A9 | Reductant Level Sensor B Circuit Range/Performance | Fuel Metering | Medium |
| P21AA | Reductant Level Sensor B Circuit Low | Fuel Metering | Medium |
| P21AB | Reductant Level Sensor B Circuit High | Fuel Metering | Medium |
| P21AC | Reductant Level Sensor B Circuit Intermittent/Erratic | Fuel Metering | Medium |
| P21AD | Reductant Level Sensor C Circuit | Fuel Metering | Medium |
| P21AE | Reductant Level Sensor C Circuit Range/Performance | Fuel Metering | Medium |
| P21AF | Reductant Level Sensor C Circuit Low | Fuel Metering | Medium |
| P21B0 | Reductant Level Sensor C Circuit High | Fuel Metering | Medium |
| P21B1 | Reductant Level Sensor C Circuit Intermittent/Erratic | Fuel Metering | Medium |
| P21B2 | Excessive Time To Enter Closed Loop NOx Adsorber Control | Fuel Metering | Medium |
| P21B3 | Closed Loop NOx Adsorber Control At Limit - Too High | Fuel Metering | Medium |
| P21B4 | NOx Adsorber - Over Temperature Bank 1 | Fuel Metering | Medium |
| P21B5 | NOx Adsorber - Over Temperature Bank 2 | Fuel Metering | Medium |
| P21C2 | Reductant Heater Relay Control Circuit/Open | Fuel Metering | Medium |
| P21C3 | Reductant Heater Relay Control Circuit Low | Fuel Metering | Medium |
| P21C4 | Reductant Heater Relay Control Circuit High | Fuel Metering | Medium |
| P21C5 | Reductant Level Sensor A Stuck | Fuel Metering | Medium |
| P21C6 | Reductant Level Sensor B Stuck | Fuel Metering | Medium |
| P21C7 | Reductant Control Module Power Relay/Relays Control Circuit/Open | Fuel Metering | Medium |
| P21C8 | Reductant Control Module Power Relay/Relays Control Circuit Low | Fuel Metering | Medium |
| P21C9 | Reductant Control Module Power Relay/Relays Control Circuit High | Fuel Metering | Medium |
| P21CA | Reductant Control Module Supply Voltage Circuit | Fuel Metering | Medium |
| P21CB | Reductant Control Module Supply Voltage Low | Fuel Metering | Medium |
| P21CC | Reductant Control Module Supply Voltage High | Fuel Metering | Medium |
| P21CD | Reductant Quality Module Supply Voltage Low | Fuel Metering | Medium |
| P21CE | Reductant Quality Module Performance | Fuel Metering | Medium |
| P21CF | Cylinder 1 Injector B Circuit/Open | Fuel Metering | Medium |
| P21D0 | Cylinder 2 Injector B Circuit/Open | Fuel Metering | Medium |
| P21D1 | Cylinder 3 Injector B Circuit/Open | Fuel Metering | Medium |
| P21D2 | Cylinder 4 Injector B Circuit/Open | Fuel Metering | Medium |
| P21D3 | Cylinder 5 Injector B Circuit/Open | Fuel Metering | Medium |
| P21D4 | Cylinder 6 Injector B Circuit/Open | Fuel Metering | Medium |
| P21D5 | Cylinder 7 Injector B Circuit/Open | Fuel Metering | Medium |
| P21D6 | Cylinder 8 Injector B Circuit/Open | Fuel Metering | Medium |
| P21D7 | Cylinder 9 Injector B Circuit/Open | Fuel Metering | Medium |
| P21D8 | Cylinder 10 Injector B Circuit/Open | Fuel Metering | Medium |
| P21D9 | Cylinder 11 Injector B Circuit/Open | Fuel Metering | Medium |
| P21DA | Cylinder 12 Injector B Circuit/Open | Fuel Metering | Medium |
| P21DB | Cylinder 1 Injector B Circuit Low | Fuel Metering | Medium |
| P21DC | Cylinder 1 Injector B Circuit High | Fuel Metering | Medium |
| P21DD | Reductant Heater A Current Too Low | Fuel Metering | Medium |
| P21DE | Cylinder 2 Injector B Circuit Low | Fuel Metering | Medium |
| P21DF | Cylinder 2 Injector B Circuit High | Fuel Metering | Medium |
| P21E0 | Cylinder 3 Injector B Circuit Low | Fuel Metering | Medium |
| P21E1 | Cylinder 3 Injector B Circuit High | Fuel Injection | Medium |
| P21EA | Cylinder 8 Injector B Circuit Low | Fuel Metering | Medium |
| P21EB | Cylinder 8 Injector B Circuit High | Fuel Metering | Medium |
| P21EC | Cylinder 9 Injector B Circuit Low | Fuel Metering | Medium |
| P21ED | Cylinder 9 Injector B Circuit High | Fuel Metering | Medium |
| P21EE | Cylinder 10 Injector B Circuit Low | Fuel Metering | Medium |
| P21EF | Cylinder 10 Injector B Circuit High | Fuel Metering | Medium |
| P21F0 | Cylinder 11 Injector B Circuit Low | Fuel Metering | Medium |
| P21F1 | Cylinder 11 Injector B Circuit High | Fuel Metering | Medium |
| P21F2 | Cylinder 12 Injector B Circuit Low | Fuel Metering | Medium |
About Fuel System Codes
This page lists all 5,039 OBD-II diagnostic trouble codes classified under the Fuel System category. These codes are stored by your vehicle's onboard computer when a sensor detects a malfunction in the fuel system system. Each code begins with a letter indicating the system (P for Powertrain, B for Body, C for Chassis, U for Network) followed by four digits that identify the specific fault.
When your check engine light comes on, an OBD-II scanner reads these stored codes to help pinpoint the problem. Generic codes (where the second digit is 0) follow the SAE J2012 standard and mean the same thing on every vehicle. Manufacturer-specific codes (where the second digit is 1) may have different meanings depending on the vehicle brand.
Click any code in the table above to see its full description, possible causes, common symptoms, and step-by-step repair guidance. Use the search box to quickly find a specific code within this category.