# OBD-II trouble codes

Type the code from your scanner, or browse below. Each page gives the meaning, ranked causes, the fix and its cost, and a plain verdict on driving.

## Most looked-up codes

| Code | Meaning | Verdict | Typical cost |
| --- | --- | --- | --- |
| [P0420](/codes/p0420) | Catalyst System Efficiency Below Threshold (Bank 1) | Drive to a shop this week | $150-$2,800 |
| [P0300](/codes/p0300) | Random/Multiple Cylinder Misfire Detected | Drive to a shop this week | $100-$2,000 |
| [P0171](/codes/p0171) | System Too Lean (Bank 1) | Drive to a shop this week | $15-$1,300 |
| [P0455](/codes/p0455) | Evaporative Emission System Leak Detected (large leak) | Safe to drive | $20-$600 |
| [P0128](/codes/p0128) | Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) | Safe to drive | $50-$600 |
| [P0442](/codes/p0442) | Evaporative Emission System Leak Detected (small leak) | Safe to drive | $20-$600 |
| [P0401](/codes/p0401) | Exhaust Gas Recirculation "A" Flow Insufficient Detected | Safe to drive | $150-$800 |
| [P0174](/codes/p0174) | System Too Lean (Bank 2) | Drive to a shop this week | $15-$1,300 |

## How to read a trouble code

Every OBD-II code has five characters. The letter is the system, the first digit says whether the code is generic or set by the carmaker, and the rest narrows it down.

| Position | Example (P0420) | Meaning |
| --- | --- | --- |
| 1st: letter | P | P = powertrain (engine, transmission), B = body, C = chassis, U = network |
| 2nd: digit | 0 | 0 = generic SAE code (same meaning on every car); 1 = manufacturer-specific |
| 3rd: digit | 4 | Subsystem: 1-2 fuel and air, 3 ignition/misfire, 4 emissions, 5 speed and idle, 6 computer, 7-9 transmission |
| 4th-5th | 20 | The specific fault |

All generic powertrain codes are listed on the [P0 codes page](/codes/p0).

## P00xx: Fuel and air metering, auxiliary emission controls

| Code | Meaning | Verdict | Typical cost |
| --- | --- | --- | --- |
| [P0010](/codes/p0010) | "A" Camshaft Position Actuator Circuit (Bank 1) | Drive to a shop this week | $100-$450 |
| [P0011](/codes/p0011) | "A" Camshaft Position - Timing Over-Advanced or System Performance (Bank 1) | Drive to a shop this week | $80-$2,500 |
| [P0012](/codes/p0012) | "A" Camshaft Position - Timing Over-Retarded (Bank 1) | Drive to a shop this week | $80-$3,000 |
| [P0013](/codes/p0013) | "B" Camshaft Position Actuator Circuit (Bank 1) | Drive to a shop this week | $100-$450 |
| [P0014](/codes/p0014) | "B" Camshaft Position - Timing Over-Advanced or System Performance (Bank 1) | Drive to a shop this week | $80-$2,500 |
| [P0015](/codes/p0015) | "B" Camshaft Position - Timing Over-Retarded (Bank 1) | Drive to a shop this week | $80-$2,800 |
| [P0016](/codes/p0016) | Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A) | Drive to a shop this week | $150-$3,000 |
| [P0017](/codes/p0017) | Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor B) | Drive to a shop this week | $150-$3,000 |
| [P0018](/codes/p0018) | Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor A) | Drive to a shop this week | $150-$3,500 |
| [P0019](/codes/p0019) | Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor B) | Drive to a shop this week | $150-$3,500 |
| [P0021](/codes/p0021) | "A" Camshaft Position - Timing Over-Advanced or System Performance (Bank 2) | Drive to a shop this week | $80-$3,000 |
| [P0030](/codes/p0030) | HO2S Heater Control Circuit (Bank 1 Sensor 1) | Safe to drive | $20-$400 |
| [P0087](/codes/p0087) | Fuel Rail/System Pressure - Too Low | Drive to a shop this week | $100-$2,200 |

## P01xx: Fuel and air metering

| Code | Meaning | Verdict | Typical cost |
| --- | --- | --- | --- |
| [P0101](/codes/p0101) | Mass or Volume Air Flow "A" Circuit Range/Performance | Drive to a shop this week | $15-$450 |
| [P0102](/codes/p0102) | Mass or Volume Air Flow "A" Circuit Low | Drive to a shop this week | $15-$450 |
| [P0106](/codes/p0106) | Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance | Drive to a shop this week | $50-$600 |
| [P0107](/codes/p0107) | Manifold Absolute Pressure/Barometric Pressure Circuit Low | Drive to a shop this week | $100-$450 |
| [P0108](/codes/p0108) | Manifold Absolute Pressure/Barometric Pressure Circuit High | Drive to a shop this week | $100-$400 |
| [P0112](/codes/p0112) | Intake Air Temperature Sensor 1 Circuit Low (Bank 1) | Safe to drive | $50-$450 |
| [P0113](/codes/p0113) | Intake Air Temperature Sensor 1 Circuit High (Bank 1) | Safe to drive | $20-$400 |
| [P0117](/codes/p0117) | Engine Coolant Temperature Sensor 1 Circuit Low | Drive to a shop this week | $100-$400 |
| [P0118](/codes/p0118) | Engine Coolant Temperature Sensor 1 Circuit High | Drive to a shop this week | $50-$400 |
| [P0121](/codes/p0121) | Throttle/Pedal Position Sensor/Switch "A" Circuit Range/Performance | Drive to a shop this week | $75-$900 |
| [P0122](/codes/p0122) | Throttle/Pedal Position Sensor/Switch "A" Circuit Low | Drive to a shop this week | $100-$900 |
| [P0123](/codes/p0123) | Throttle/Pedal Position Sensor/Switch "A" Circuit High | Drive to a shop this week | $100-$900 |
| [P0125](/codes/p0125) | Insufficient Coolant Temperature for Closed Loop Fuel Control | Safe to drive | $30-$600 |
| [P0128](/codes/p0128) | Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) | Safe to drive | $50-$600 |
| [P0130](/codes/p0130) | O2 Sensor Circuit (Bank 1 Sensor 1) | Safe to drive | $100-$450 |
| [P0131](/codes/p0131) | O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1) | Safe to drive | $100-$400 |
| [P0132](/codes/p0132) | O2 Sensor Circuit High Voltage (Bank 1 Sensor 1) | Safe to drive | $100-$450 |
| [P0133](/codes/p0133) | O2 Sensor Circuit Slow Response (Bank 1 Sensor 1) | Safe to drive | $100-$400 |
| [P0134](/codes/p0134) | O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1) | Safe to drive | $20-$450 |
| [P0135](/codes/p0135) | O2 Sensor Heater Circuit (Bank 1 Sensor 1) | Safe to drive | $20-$400 |
| [P0136](/codes/p0136) | O2 Sensor Circuit (Bank 1 Sensor 2) | Safe to drive | $100-$400 |
| [P0137](/codes/p0137) | O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2) | Safe to drive | $100-$400 |
| [P0138](/codes/p0138) | O2 Sensor Circuit High Voltage (Bank 1 Sensor 2) | Safe to drive | $100-$400 |
| [P0139](/codes/p0139) | O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) | Safe to drive | $150-$400 |
| [P0140](/codes/p0140) | O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2) | Safe to drive | $20-$400 |
| [P0141](/codes/p0141) | O2 Sensor Heater Circuit (Bank 1 Sensor 2) | Safe to drive | $20-$350 |
| [P0151](/codes/p0151) | O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1) | Safe to drive | $100-$600 |
| [P0153](/codes/p0153) | O2 Sensor Circuit Slow Response (Bank 2 Sensor 1) | Safe to drive | $150-$550 |
| [P0155](/codes/p0155) | O2 Sensor Heater Circuit (Bank 2 Sensor 1) | Safe to drive | $20-$500 |
| [P0156](/codes/p0156) | O2 Sensor Circuit (Bank 2 Sensor 2) | Safe to drive | $100-$400 |
| [P0157](/codes/p0157) | O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2) | Safe to drive | $100-$450 |
| [P0158](/codes/p0158) | O2 Sensor Circuit High Voltage (Bank 2 Sensor 2) | Safe to drive | $100-$400 |
| [P0161](/codes/p0161) | O2 Sensor Heater Circuit (Bank 2 Sensor 2) | Safe to drive | $20-$400 |
| [P0171](/codes/p0171) | System Too Lean (Bank 1) | Drive to a shop this week | $15-$1,300 |
| [P0172](/codes/p0172) | System Too Rich (Bank 1) | Drive to a shop this week | $15-$1,200 |
| [P0174](/codes/p0174) | System Too Lean (Bank 2) | Drive to a shop this week | $15-$1,300 |
| [P0175](/codes/p0175) | System Too Rich (Bank 2) | Drive to a shop this week | $15-$1,200 |
| [P0191](/codes/p0191) | Fuel Rail Pressure Sensor "A" Circuit Range/Performance | Drive to a shop this week | $100-$2,200 |

## P02xx: Fuel and air metering (injector circuit)

| Code | Meaning | Verdict | Typical cost |
| --- | --- | --- | --- |
| [P0201](/codes/p0201) | Injector Circuit/Open - Cylinder 1 | Drive to a shop this week | $100-$1,100 |
| [P0217](/codes/p0217) | Engine Coolant Over Temperature Condition | Stop driving | $50-$3,500 |
| [P0230](/codes/p0230) | Fuel Pump Primary Circuit | Drive to a shop this week | $20-$1,300 |
| [P0261](/codes/p0261) | Cylinder 1 Injector "A" Circuit Low | Drive to a shop this week | $100-$1,100 |
| [P0299](/codes/p0299) | Turbocharger/Supercharger "A" Underboost Condition | Drive to a shop this week | $100-$4,000 |

## P03xx: Ignition system or misfire

| Code | Meaning | Verdict | Typical cost |
| --- | --- | --- | --- |
| [P0300](/codes/p0300) | Random/Multiple Cylinder Misfire Detected | Drive to a shop this week | $100-$2,000 |
| [P0301](/codes/p0301) | Cylinder 1 Misfire Detected | Drive to a shop this week | $100-$1,500 |
| [P0302](/codes/p0302) | Cylinder 2 Misfire Detected | Drive to a shop this week | $100-$1,500 |
| [P0303](/codes/p0303) | Cylinder 3 Misfire Detected | Drive to a shop this week | $100-$1,500 |
| [P0304](/codes/p0304) | Cylinder 4 Misfire Detected | Drive to a shop this week | $100-$2,500 |
| [P0305](/codes/p0305) | Cylinder 5 Misfire Detected | Drive to a shop this week | $150-$1,500 |
| [P0306](/codes/p0306) | Cylinder 6 Misfire Detected | Drive to a shop this week | $100-$1,500 |
| [P0307](/codes/p0307) | Cylinder 7 Misfire Detected | Drive to a shop this week | $150-$4,500 |
| [P0308](/codes/p0308) | Cylinder 8 Misfire Detected | Drive to a shop this week | $150-$3,500 |
| [P0316](/codes/p0316) | Engine Misfire Detected on Startup (First 1000 Revolutions) | Drive to a shop this week | $120-$3,500 |
| [P0320](/codes/p0320) | Ignition/Distributor Engine Speed Input Circuit | Drive to a shop this week | $100-$1,800 |
| [P0325](/codes/p0325) | Knock Sensor 1 Circuit (Bank 1 or Single Sensor) | Drive to a shop this week | $150-$1,200 |
| [P0326](/codes/p0326) | Knock Sensor 1 Circuit Range/Performance (Bank 1 or Single Sensor) | Drive to a shop this week | $150-$1,200 |
| [P0327](/codes/p0327) | Knock Sensor 1 Circuit Low (Bank 1 or Single Sensor) | Drive to a shop this week | $150-$1,200 |
| [P0332](/codes/p0332) | Knock Sensor 2 Circuit Low (Bank 2) | Drive to a shop this week | $150-$1,300 |
| [P0335](/codes/p0335) | Crankshaft Position Sensor "A" Circuit | Drive to a shop this week | $150-$600 |
| [P0336](/codes/p0336) | Crankshaft Position Sensor "A" Circuit Range/Performance | Drive to a shop this week | $150-$2,000 |
| [P0339](/codes/p0339) | Crankshaft Position Sensor "A" Circuit Intermittent | Drive to a shop this week | $100-$450 |
| [P0340](/codes/p0340) | Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor) | Drive to a shop this week | $120-$450 |
| [P0341](/codes/p0341) | Camshaft Position Sensor "A" Circuit Range/Performance (Bank 1 or Single Sensor) | Drive to a shop this week | $120-$2,500 |
| [P0344](/codes/p0344) | Camshaft Position Sensor "A" Circuit Intermittent (Bank 1 or Single Sensor) | Drive to a shop this week | $100-$400 |
| [P0345](/codes/p0345) | Camshaft Position Sensor "A" Circuit (Bank 2) | Drive to a shop this week | $120-$450 |
| [P0351](/codes/p0351) | Ignition Coil "A" Primary/Secondary Circuit | Drive to a shop this week | $150-$500 |
| [P0352](/codes/p0352) | Ignition Coil "B" Primary/Secondary Circuit | Drive to a shop this week | $100-$700 |
| [P0365](/codes/p0365) | Camshaft Position Sensor "B" Circuit (Bank 1) | Drive to a shop this week | $120-$400 |

## P04xx: Auxiliary emission controls

| Code | Meaning | Verdict | Typical cost |
| --- | --- | --- | --- |
| [P0400](/codes/p0400) | Exhaust Gas Recirculation "A" Flow | Safe to drive | $150-$800 |
| [P0401](/codes/p0401) | Exhaust Gas Recirculation "A" Flow Insufficient Detected | Safe to drive | $150-$800 |
| [P0402](/codes/p0402) | Exhaust Gas Recirculation "A" Flow Excessive Detected | Drive to a shop this week | $100-$750 |
| [P0403](/codes/p0403) | Exhaust Gas Recirculation "A" Control Circuit | Safe to drive | $100-$750 |
| [P0404](/codes/p0404) | Exhaust Gas Recirculation "A" Control Circuit Range/Performance | Drive to a shop this week | $150-$750 |
| [P0405](/codes/p0405) | Exhaust Gas Recirculation Sensor "A" Circuit Low | Safe to drive | $100-$750 |
| [P0406](/codes/p0406) | Exhaust Gas Recirculation Sensor "A" Circuit High | Safe to drive | $100-$750 |
| [P0410](/codes/p0410) | Secondary Air Injection System "A" | Safe to drive | $150-$1,200 |
| [P0411](/codes/p0411) | Secondary Air Injection System "A" Incorrect Flow Detected | Safe to drive | $150-$1,200 |
| [P0420](/codes/p0420) | Catalyst System Efficiency Below Threshold (Bank 1) | Drive to a shop this week | $150-$2,800 |
| [P0421](/codes/p0421) | Warm Up Catalyst Efficiency Below Threshold (Bank 1) | Drive to a shop this week | $150-$2,600 |
| [P0430](/codes/p0430) | Catalyst System Efficiency Below Threshold (Bank 2) | Drive to a shop this week | $150-$2,800 |
| [P0431](/codes/p0431) | Warm Up Catalyst Efficiency Below Threshold (Bank 2) | Drive to a shop this week | $150-$2,800 |
| [P0440](/codes/p0440) | Evaporative Emission System | Safe to drive | $20-$600 |
| [P0441](/codes/p0441) | Evaporative Emission System Incorrect Purge Flow | Safe to drive | $100-$600 |
| [P0442](/codes/p0442) | Evaporative Emission System Leak Detected (small leak) | Safe to drive | $20-$600 |
| [P0443](/codes/p0443) | Evaporative Emission System Purge Control Valve "A" Circuit | Safe to drive | $80-$450 |
| [P0446](/codes/p0446) | Evaporative Emission System Vent Control Circuit | Safe to drive | $100-$500 |
| [P0449](/codes/p0449) | Evaporative Emission System Vent Valve/Solenoid Circuit | Safe to drive | $100-$450 |
| [P0451](/codes/p0451) | Evaporative Emission System Pressure Sensor/Switch "A" Circuit Range/Performance | Safe to drive | $100-$1,100 |
| [P0452](/codes/p0452) | Evaporative Emission System Pressure Sensor/Switch "A" Circuit Low | Safe to drive | $100-$1,100 |
| [P0455](/codes/p0455) | Evaporative Emission System Leak Detected (large leak) | Safe to drive | $20-$600 |
| [P0456](/codes/p0456) | Evaporative Emission System Leak Detected (very small leak) | Safe to drive | $20-$600 |
| [P0457](/codes/p0457) | Evaporative Emission System Leak Detected (fuel cap loose/off) | Safe to drive | $20-$700 |
| [P0491](/codes/p0491) | Secondary Air Injection System Insufficient Flow Bank 1 | Safe to drive | $50-$1,500 |
| [P0496](/codes/p0496) | Evaporative Emission System High Purge Flow | Drive to a shop this week | $120-$650 |
| [P0498](/codes/p0498) | Evaporative Emission System Vent Valve Control Circuit Low | Safe to drive | $100-$450 |

## P05xx: Vehicle speed, idle control and auxiliary inputs

| Code | Meaning | Verdict | Typical cost |
| --- | --- | --- | --- |
| [P0500](/codes/p0500) | Vehicle Speed Sensor "A" | Drive to a shop this week | $120-$500 |
| [P0505](/codes/p0505) | Idle Air Control System | Drive to a shop this week | $80-$900 |
| [P0506](/codes/p0506) | Idle Air Control System RPM Lower Than Expected | Safe to drive | $80-$900 |
| [P0507](/codes/p0507) | Idle Air Control System RPM Higher Than Expected | Safe to drive | $80-$900 |
| [P0520](/codes/p0520) | Engine Oil Pressure Sensor/Switch "A" Circuit | Drive to a shop this week | $100-$450 |
| [P0521](/codes/p0521) | Engine Oil Pressure Sensor/Switch "A" Circuit Range/Performance | Stop driving | $60-$2,500 |
| [P0522](/codes/p0522) | Engine Oil Pressure Sensor/Switch "A" Circuit Low | Stop driving | $100-$450 |
| [P0523](/codes/p0523) | Engine Oil Pressure Sensor/Switch "A" Circuit High | Drive to a shop this week | $100-$400 |
| [P0524](/codes/p0524) | Engine Oil Pressure Too Low | Stop driving | $80-$8,500 |
| [P0562](/codes/p0562) | System Voltage Low | Drive to a shop this week | $30-$900 |
| [P0571](/codes/p0571) | Brake Switch "A" Circuit | Drive to a shop this week | $50-$400 |

## P06xx: Computer and output circuits

| Code | Meaning | Verdict | Typical cost |
| --- | --- | --- | --- |
| [P0601](/codes/p0601) | Internal Control Module Memory Check Sum Error | Drive to a shop this week | $100-$1,800 |
| [P0606](/codes/p0606) | Control Module Processor | Drive to a shop this week | $100-$2,000 |

## P07xx: Transmission

| Code | Meaning | Verdict | Typical cost |
| --- | --- | --- | --- |
| [P0700](/codes/p0700) | Transmission Control System (MIL Request) | Drive to a shop this week | $100-$5,500 |
| [P0705](/codes/p0705) | Transmission Range Sensor "A" Circuit (PRNDL Input) | Drive to a shop this week | $80-$1,100 |
| [P0715](/codes/p0715) | Input/Turbine Speed Sensor "A" Circuit | Drive to a shop this week | $150-$700 |
| [P0717](/codes/p0717) | Input/Turbine Speed Sensor "A" Circuit No Signal | Drive to a shop this week | $100-$900 |
| [P0720](/codes/p0720) | Output Shaft Speed Sensor "A" Circuit | Drive to a shop this week | $100-$750 |
| [P0730](/codes/p0730) | Incorrect Gear Ratio | Drive to a shop this week | $150-$5,500 |
| [P0731](/codes/p0731) | Gear 1 Incorrect Ratio | Drive to a shop this week | $150-$5,500 |
| [P0732](/codes/p0732) | Gear 2 Incorrect Ratio | Drive to a shop this week | $150-$5,500 |
| [P0740](/codes/p0740) | Torque Converter Clutch Solenoid Circuit/Open | Drive to a shop this week | $100-$1,200 |
| [P0741](/codes/p0741) | Torque Converter Clutch Solenoid Circuit Performance/Stuck Off | Drive to a shop this week | $150-$2,800 |
| [P0750](/codes/p0750) | Shift Solenoid "A" | Drive to a shop this week | $100-$1,600 |

## P08xx: Transmission

| Code | Meaning | Verdict | Typical cost |
| --- | --- | --- | --- |
| [P0841](/codes/p0841) | Transmission Fluid Pressure Sensor/Switch "A" Circuit Range/Performance | Drive to a shop this week | $150-$5,500 |

## Frequently asked questions

### Can I clear a check engine code myself?

Yes, a basic OBD-II scanner can clear codes, and so can disconnecting the battery on many cars. But clearing a code does not fix the fault: if the problem is still there the light comes back, and the car will show "not ready" at an emissions test until it has been driven enough to rerun its self-tests.

### Where is the OBD-II port?

On almost every car sold in the US since 1996 it is under the dashboard on the driver side, within reach of the steering column. It is a 16-pin trapezoid-shaped socket; some cars hide it behind a small cover.

### Do auto parts stores read codes for free?

Many US auto parts chains will read your codes for free in the parking lot. A basic Bluetooth OBD-II reader costs about $20-$40 if you would rather check it yourself.

## Warning lights

- [ABS warning light](https://diagxcar.com/warning-lights/abs)
- [Airbag (SRS) warning light](https://diagxcar.com/warning-lights/airbag)
- [Battery (charging system) warning light](https://diagxcar.com/warning-lights/battery)
- [Brake warning light](https://diagxcar.com/warning-lights/brake)
- [Check engine light](https://diagxcar.com/warning-lights/check-engine)
- [Coolant temperature warning light](https://diagxcar.com/warning-lights/coolant-temperature)

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Source page: https://diagxcar.com/codes
General information, not a substitute for a qualified mechanic.