P21xx codes: Fuel and air metering
256 powertrain trouble codes from P2100 to P21FF. They mostly involve the fuel injector, engine control module, injector wiring and ECM.
All P21xx codes
252 of these codes usually turn on the check engine light; 95 can often be fixed at home.
| Code | Meaning | Difficulty |
|---|---|---|
| P2100 | Throttle Actuator A Control Motor Circuit/Open | Medium |
| P2101 | Throttle Actuator A Control Motor Circuit Range/Performance | Medium |
| P2102 | Throttle Actuator A Control Motor Circuit Low | Medium |
| P2103 | Throttle Actuator A Control Motor Circuit High | Medium |
| P2104 | Throttle Actuator Control System - Forced Idle | Medium |
| P2105 | Throttle Actuator Control System - Forced Engine Shutdown | Workshop only |
| P2106 | Throttle Actuator Control System - Forced Limited Power | Medium |
| P2107 | Throttle Actuator A Control Module Processor | Workshop only |
| P2108 | Throttle Actuator A Control Module Performance | Medium |
| P2109 | Throttle/Pedal Position Sensor A Minimum Stop Performance | Medium |
| P210A | Throttle Actuator B Control Motor Circuit/Open | Medium |
| P210B | Throttle Actuator B Control Motor Circuit Range/Performance | Medium |
| P210C | Throttle Actuator B Control Motor Circuit Low | Medium |
| P210D | Throttle Actuator B Control Motor Circuit High | Medium |
| P210E | Throttle/Pedal Position Sensor/Switch C/F Voltage Correlation | Medium |
| P210F | Throttle Actuator B Control System - Forced Limited RPM | Medium |
| P2110 | Throttle Actuator A Control System - Forced Limited RPM | Medium |
| P2111 | Throttle Actuator A Control System - Stuck Open | Medium |
| P2112 | Throttle Actuator A Control System - Stuck Closed | Medium |
| P2113 | Throttle/Pedal Position Sensor B Minimum Stop Performance | Medium |
| P2114 | Throttle/Pedal Position Sensor C Minimum Stop Performance | Medium |
| P2115 | Throttle/Pedal Position Sensor D Minimum Stop Performance | Easy |
| P2116 | Throttle/Pedal Position Sensor E Minimum Stop Performance | Easy |
| P2117 | Throttle/Pedal Position Sensor F Minimum Stop Performance | Easy |
| P2118 | Throttle Actuator A Control Motor Current Range/Performance | Medium |
| P2119 | Throttle Actuator A Control Throttle Body Range/Performance | Medium |
| P211A | Throttle Actuator B Control System - Stuck Open | Medium |
| P211B | Throttle Actuator B Control System - Stuck Closed | Medium |
| P211C | Throttle Actuator B Control Motor Current Range/Performance | Medium |
| P211D | Throttle Actuator B Control Throttle Body Range/Performance | Medium |
| P211E | Throttle Actuator B Control Module Processor | Workshop only |
| P211F | Throttle Actuator B Control Module Performance | Medium |
| P2120 | Throttle/Pedal Position Sensor/Switch D Circuit | Easy |
| P2121 | Throttle/Pedal Position Sensor/Switch D Circuit Range/Performance | Easy |
| P2122 | Throttle/Pedal Position Sensor/Switch D Circuit Low | Easy |
| P2123 | Throttle/Pedal Position Sensor/Switch D Circuit High | Easy |
| P2124 | Throttle/Pedal Position Sensor/Switch D Circuit Intermittent | Medium |
| P2125 | Throttle/Pedal Position Sensor/Switch E Circuit | Easy |
| P2126 | Throttle/Pedal Position Sensor/Switch E Circuit Range/Performance | Easy |
| P2127 | Throttle/Pedal Position Sensor/Switch E Circuit Low | Easy |
| P2128 | Throttle/Pedal Position Sensor/Switch E Circuit High | Easy |
| P2129 | Throttle/Pedal Position Sensor/Switch E Circuit Intermittent | Medium |
| P212A | Throttle Position Sensor/Switch G Circuit | Medium |
| P212B | Throttle Position Sensor/Switch G Circuit Range/Performance | Medium |
| P212C | Throttle Position Sensor/Switch G Circuit Low | Medium |
| P212D | Throttle Position Sensor/Switch G Circuit High | Medium |
| P212E | Throttle Position Sensor/Switch G Circuit Intermittent | Medium |
| P212F | Throttle/Pedal Position Sensor/Switch F/G Voltage Correlation | Medium |
| P2130 | Throttle/Pedal Position Sensor/Switch F Circuit | Easy |
| P2131 | Throttle/Pedal Position Sensor/Switch F Circuit Range/Performance | Easy |
| P2132 | Throttle/Pedal Position Sensor/Switch F Circuit Low | Easy |
| P2133 | Throttle/Pedal Position Sensor/Switch F Circuit High | Easy |
| P2134 | Throttle/Pedal Position Sensor/Switch F Circuit Intermittent | Easy |
| P2135 | Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation | Medium |
| P2136 | Throttle/Pedal Position Sensor/Switch A/C Voltage Correlation | Medium |
| P2137 | Throttle/Pedal Position Sensor/Switch B/C Voltage Correlation | Medium |
| P2138 | Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation | Easy |
| P2139 | Throttle/Pedal Position Sensor/Switch D/F Voltage Correlation | Easy |
| P213A | EGR Throttle Control Circuit B/Open | Medium |
| P213B | EGR Throttle Control Circuit B Range/Performance | Medium |
| P213C | EGR Throttle Control Circuit B Low | Medium |
| P213D | EGR Throttle Control Circuit B High | Medium |
| P213E | Fuel Injection System Fault - Forced Engine Shutdown | Workshop only |
| P213F | Fuel Pump System Fault - Forced Engine Shutdown | Hard |
| P2140 | Throttle/Pedal Position Sensor/Switch E/F Voltage Correlation | Easy |
| P2141 | EGR Throttle Control Circuit A Low | Medium |
| P2142 | EGR Throttle Control Circuit A High | Medium |
| P2143 | EGR Vent Control Circuit/Open | Easy |
| P2144 | EGR Vent Control Circuit Low | Easy |
| P2145 | EGR Vent Control Circuit High | Easy |
| P2146 | Fuel Injector Group A Supply Voltage Circuit/Open | Hard |
| P2147 | Fuel Injector Group A Supply Voltage Circuit Low | Hard |
| P2148 | Fuel Injector Group A Supply Voltage Circuit High | Hard |
| P2149 | Fuel Injector Group B Supply Voltage Circuit/Open | Hard |
| P214A | SCR NOx Catalyst Inlet Temperature Too High | Hard |
| P214B | SCR NOx Catalyst Inlet Temperature Too High During Particulate Filter Regeneration | Hard |
| P214C | SCR NOx Catalyst Outlet Temperature Too High | Medium |
| P214D | SCR NOx Catalyst Outlet Temperature Too High During Particulate Filter Regeneration | Medium |
| P214E | Reductant Pump A Current Too High | Medium |
| P214F | Reductant Heater A Current Too High | Medium |
| P2150 | Fuel Injector Group B Supply Voltage Circuit Low | Hard |
| P2151 | Fuel Injector Group B Supply Voltage Circuit High | Hard |
| P2152 | Fuel Injector Group C Supply Voltage Circuit/Open | Hard |
| P2153 | Fuel Injector Group C Supply Voltage Circuit Low | Hard |
| P2154 | Fuel Injector Group C Supply Voltage Circuit High | Hard |
| P2155 | Fuel Injector Group D Supply Voltage Circuit/Open | Hard |
| P2156 | Fuel Injector Group D Supply Voltage Circuit Low | Hard |
| P2157 | Fuel Injector Group D Supply Voltage Circuit High | Hard |
| P2158 | Vehicle Speed Sensor B Circuit | Medium |
| P2159 | Vehicle Speed Sensor B Circuit Range/Performance | Hard |
| P215A | Vehicle Speed - Wheel Speed Correlation | Medium |
| P215B | Vehicle Speed - Output Shaft Speed Correlation | Medium |
| P215C | Output Shaft Speed - Wheel Speed Correlation | Medium |
| P215D | Reductant Pump B Stuck On | Medium |
| P215E | Reductant Heater D Current Too Low | Medium |
| P215F | Reductant Heater D Current Too High | Medium |
| P2160 | Vehicle Speed Sensor B Circuit Low | Medium |
| P2161 | Vehicle Speed Sensor B Circuit Intermittent/Erratic/High | Medium |
| P2162 | Vehicle Speed Sensor A/B Correlation | Medium |
| P2163 | Throttle/Pedal Position Sensor A Maximum Stop Performance | Medium |
| P2164 | Throttle/Pedal Position Sensor B Maximum Stop Performance | Medium |
| P2165 | Throttle/Pedal Position Sensor C Maximum Stop Performance | Medium |
| P2166 | Throttle/Pedal Position Sensor D Maximum Stop Performance | Easy |
| P2167 | Throttle/Pedal Position Sensor E Maximum Stop Performance | Easy |
| P2168 | Throttle/Pedal Position Sensor F Maximum Stop Performance | Easy |
| P2169 | Exhaust Pressure Regulator Vent Solenoid Control Circuit/Open | Medium |
| P216A | Fuel Injector Group E Supply Voltage Circuit/Open | Hard |
| P216B | Fuel Injector Group E Supply Voltage Circuit Low | Hard |
| P216C | Fuel Injector Group E Supply Voltage Circuit High | Hard |
| P216D | Fuel Injector Group F Supply Voltage Circuit/Open | Hard |
| P216E | Fuel Injector Group F Supply Voltage Circuit Low | Hard |
| P216F | Fuel Injector Group F Supply Voltage Circuit High | Hard |
| P2170 | Exhaust Pressure Regulator Vent Solenoid Control Circuit Low | Medium |
| P2171 | Exhaust Pressure Regulator Vent Solenoid Control Circuit High | Medium |
| P2172 | Throttle Actuator Control System - Sudden High Air Flow Detected | Medium |
| P2173 | Throttle Actuator Control System - High Air Flow Detected | Medium |
| P2174 | Throttle Actuator Control System - Sudden Low Air Flow Detected | Medium |
| P2175 | Throttle Actuator Control System - Low Air Flow Detected | Easy |
| P2176 | Throttle Actuator A Control System - Idle Position Not Learned | Easy |
| P2177 | System Too Lean Off Idle (Bank 1) | Medium |
| P2178 | System Too Rich Off Idle (Bank 1) | Medium |
| P2179 | System Too Lean Off Idle (Bank 2) | Medium |
| P217A | Fuel Injector Group G Supply Voltage Circuit/Open | Hard |
| P217B | Fuel Injector Group G Supply Voltage Circuit Low | Hard |
| P217C | Fuel Injector Group G Supply Voltage Circuit High | Hard |
| P217D | Fuel Injector Group H Supply Voltage Circuit/Open | Hard |
| P217E | Fuel Injector Group H Supply Voltage Circuit Low | Hard |
| P217F | Fuel Injector Group H Supply Voltage Circuit High | Hard |
| P2180 | System Too Rich Off Idle (Bank 2) | Medium |
| P2181 | Cooling System Performance | Medium |
| P2182 | Engine Coolant Temperature Sensor 2 Circuit | Easy |
| P2183 | Engine Coolant Temperature Sensor 2 Circuit Range/Performance | Easy |
| P2184 | Engine Coolant Temperature Sensor 2 Circuit Low | Easy |
| P2185 | Engine Coolant Temperature Sensor 2 Circuit High | Easy |
| P2186 | Engine Coolant Temperature Sensor 2 Circuit Intermittent/Erratic | Easy |
| P2187 | System Too Lean at Idle (Bank 1) | Medium |
| P2188 | System Too Rich at Idle (Bank 1) | Medium |
| P2189 | System Too Lean at Idle (Bank 2) | Medium |
| P218A | Throttle Actuator B Control System - Idle Position Not Learned | Medium |
| P218B | Throttle/Fuel Inhibit B Circuit | Medium |
| P218C | Throttle/Fuel Inhibit B Circuit Range/Performance | Hard |
| P218D | Throttle/Fuel Inhibit B Circuit Low | Medium |
| P218E | Throttle/Fuel Inhibit B Circuit High | Medium |
| P218F | Reductant No Flow Detected | Hard |
| P2190 | System Too Rich at Idle (Bank 2) | Medium |
| P2191 | System Too Lean at Higher Load (Bank 1) | Medium |
| P2192 | System Too Rich at Higher Load (Bank 1) | Medium |
| P2193 | System Too Lean at Higher Load (Bank 2) | Medium |
| P2194 | System Too Rich at Higher Load (Bank 2) | Medium |
| P2195 | O2 Sensor Signal Biased/Stuck Lean (Bank 1, Sensor 1) | Medium |
| P2196 | O2 Sensor Signal Biased/Stuck Rich (Bank 1, Sensor 1) | Medium |
| P2197 | O2 Sensor Signal Biased/Stuck Lean (Bank 2, Sensor 1) | Medium |
| P2198 | O2 Sensor Signal Biased/Stuck Rich (Bank 2, Sensor 1) | Medium |
| P2199 | Intake Air Temperature Sensor 1/2 Correlation | Easy |
| P219A | Bank 1 Air-Fuel Ratio Imbalance | Medium |
| P219B | Bank 2 Air-Fuel Ratio Imbalance | Medium |
| P219C | Cylinder 1 Air-Fuel Ratio Imbalance | Medium |
| P219D | Cylinder 2 Air-Fuel Ratio Imbalance | Medium |
| P219E | Cylinder 3 Air-Fuel Ratio Imbalance | Hard |
| P219F | Cylinder 4 Air-Fuel Ratio Imbalance | Medium |
| P21A0 | Cylinder 5 Air-Fuel Ratio Imbalance | Medium |
| P21A1 | Cylinder 6 Air-Fuel Ratio Imbalance | Medium |
| P21A2 | Cylinder 7 Air-Fuel Ratio Imbalance | Medium |
| P21A3 | Cylinder 8 Air-Fuel Ratio Imbalance | Medium |
| P21A4 | Cylinder 9 Air-Fuel Ratio Imbalance | Hard |
| P21A5 | Cylinder 10 Air-Fuel Ratio Imbalance | Hard |
| P21A6 | Cylinder 11 Air-Fuel Ratio Imbalance | Hard |
| P21A7 | Cylinder 12 Air-Fuel Ratio Imbalance | Hard |
| P21A8 | Reductant Level Sensor B Circuit | Medium |
| P21A9 | Reductant Level Sensor B Circuit Range/Performance | Medium |
| P21AA | Reductant Level Sensor B Circuit Low | Medium |
| P21AB | Reductant Level Sensor B Circuit High | Medium |
| P21AC | Reductant Level Sensor B Circuit Intermittent/Erratic | Medium |
| P21AD | Reductant Level Sensor C Circuit | Medium |
| P21AE | Reductant Level Sensor C Circuit Range/Performance | Medium |
| P21AF | Reductant Level Sensor C Circuit Low | Medium |
| P21B0 | Reductant Level Sensor C Circuit High | Medium |
| P21B1 | Reductant Level Sensor C Circuit Intermittent/Erratic | Medium |
| P21B2 | Excessive Time To Enter Closed Loop NOx Adsorber Control | Medium |
| P21B3 | Closed Loop NOx Adsorber Control At Limit - Too High | Hard |
| P21B4 | NOx Adsorber - Over Temperature (Bank 1) | Hard |
| P21B5 | NOx Adsorber - Over Temperature (Bank 2) | Hard |
| P21B6 | Cold Start Cylinder 1 Injection Timing | Hard |
| P21B7 | Cold Start Cylinder 2 Injection Timing | Hard |
| P21B8 | Cold Start Cylinder 3 Injection Timing | Hard |
| P21B9 | Cold Start Cylinder 4 Injection Timing | Hard |
| P21BA | Cold Start Cylinder 5 Injection Timing | Hard |
| P21BB | Cold Start Cylinder 6 Injection Timing | Hard |
| P21BC | Cold Start Cylinder 7 Injection Timing | Hard |
| P21BD | Cold Start Cylinder 8 Injection Timing | Hard |
| P21BE | Cold Start Cylinder 9 Injection Timing | Workshop only |
| P21BF | Cold Start Cylinder 10 Injection Timing | Workshop only |
| P21C0 | Cold Start Cylinder 11 Injection Timing | Workshop only |
| P21C1 | Cold Start Cylinder 12 Injection Timing | Workshop only |
| P21C2 | Reductant Heater Relay Control Circuit/Open | Medium |
| P21C3 | Reductant Heater Relay Control Circuit Low | Medium |
| P21C4 | Reductant Heater Relay Control Circuit High | Medium |
| P21C5 | Reductant Level Sensor A Stuck | Medium |
| P21C6 | Reductant Level Sensor B Stuck | Medium |
| P21C7 | Reductant Control Module Power Relay/Relays Control Circuit/Open | Medium |
| P21C8 | Reductant Control Module Power Relay/Relays Control Circuit Low | Medium |
| P21C9 | Reductant Control Module Power Relay/Relays Control Circuit High | Medium |
| P21CA | Reductant Control Module Supply Voltage Circuit | Medium |
| P21CB | Reductant Control Module Supply Voltage Low | Medium |
| P21CC | Reductant Control Module Supply Voltage High | Medium |
| P21CD | Reductant Quality Module Supply Voltage Low | Medium |
| P21CE | Reductant Quality Module Performance | Medium |
| P21CF | Cylinder 1 Injector B Circuit/Open | Medium |
| P21D0 | Cylinder 2 Injector B Circuit/Open | Medium |
| P21D1 | Cylinder 3 Injector B Circuit/Open | Medium |
| P21D2 | Cylinder 4 Injector B Circuit/Open | Medium |
| P21D3 | Cylinder 5 Injector B Circuit/Open | Medium |
| P21D4 | Cylinder 6 Injector B Circuit/Open | Medium |
| P21D5 | Cylinder 7 Injector B Circuit/Open | Medium |
| P21D6 | Cylinder 8 Injector B Circuit/Open | Medium |
| P21D7 | Cylinder 9 Injector B Circuit/Open | Hard |
| P21D8 | Cylinder 10 Injector B Circuit/Open | Hard |
| P21D9 | Cylinder 11 Injector B Circuit/Open | Hard |
| P21DA | Cylinder 12 Injector B Circuit/Open | Hard |
| P21DB | Cylinder 1 Injector B Circuit Low | Hard |
| P21DC | Cylinder 1 Injector B Circuit High | Hard |
| P21DD | Reductant Heater A Current Too Low | Medium |
| P21DE | Cylinder 2 Injector B Circuit Low | Hard |
| P21DF | Cylinder 2 Injector B Circuit High | Hard |
| P21E0 | Cylinder 3 Injector B Circuit Low | Hard |
| P21E1 | Cylinder 3 Injector B Circuit High | Hard |
| P21E2 | Cylinder 4 Injector B Circuit Low | Hard |
| P21E3 | Cylinder 4 Injector B Circuit High | Hard |
| P21E4 | Cylinder 5 Injector B Circuit Low | Hard |
| P21E5 | Cylinder 5 Injector B Circuit High | Hard |
| P21E6 | Cylinder 6 Injector B Circuit Low | Hard |
| P21E7 | Cylinder 6 Injector B Circuit High | Hard |
| P21E8 | Cylinder 7 Injector B Circuit Low | Hard |
| P21E9 | Cylinder 7 Injector B Circuit High | Hard |
| P21EA | Cylinder 8 Injector B Circuit Low | Hard |
| P21EB | Cylinder 8 Injector B Circuit High | Hard |
| P21EC | Cylinder 9 Injector B Circuit Low | Hard |
| P21ED | Cylinder 9 Injector B Circuit High | Hard |
| P21EE | Cylinder 10 Injector B Circuit Low | Hard |
| P21EF | Cylinder 10 Injector B Circuit High | Hard |
| P21F0 | Cylinder 11 Injector B Circuit Low | Hard |
| P21F1 | Cylinder 11 Injector B Circuit High | Hard |
| P21F2 | Cylinder 12 Injector B Circuit Low | Hard |
| P21F3 | Cylinder 12 Injector B Circuit High | Hard |
| P21F4 | Fuel Control System B Too Lean Off Idle (Bank 1) | Medium |
| P21F5 | Fuel Control System B Too Rich Off Idle (Bank 1) | Medium |
| P21F6 | Fuel Control System B Too Lean Off Idle (Bank 2) | Medium |
| P21F7 | Fuel Control System B Too Rich Off Idle (Bank 2) | Medium |
| P21F8 | Fuel Control System B Too Lean at Idle (Bank 1) | Medium |
| P21F9 | Fuel Control System B Too Rich at Idle (Bank 1) | Medium |
| P21FA | Fuel Control System B Too Lean at Idle (Bank 2) | Medium |
| P21FB | Fuel Control System B Too Rich at Idle (Bank 2) | Medium |
| P21FC | Fuel Control System B Too Lean at Higher Load (Bank 1) | Medium |
| P21FD | Fuel Control System B Too Rich at Higher Load (Bank 1) | Medium |
| P21FE | Fuel Control System B Too Lean at Higher Load (Bank 2) | Medium |
| P21FF | Fuel Control System B Too Rich at Higher Load (Bank 2) | Medium |