Cause
Signal wire shorted to voltage
A sensor signal wire touching a supply, so the module reads the highest value the circuit allows. This often damages the module input as well, so the short has to be repaired before a replacement sensor goes in.
Typically a moderate job.
Some of these codes mean you should stop driving
1 of the 23 codes this can cause indicate a fault where continuing to drive risks damage or is unsafe. Which one you have matters more than the cause does — read the code's own page before deciding.
Codes this can cause (23)
Codes where this is a likely explanation first, rather than merely a possible one.
- P0406 Exhaust Gas Recirculation Sensor A Circuit High Low
- P0408 Exhaust Gas Recirculation Sensor B Circuit High Low
- P0428 Catalyst Temperature Sensor Circuit High Bank 1 Sensor 1 Low
- P0438 Catalyst Temperature Sensor Circuit High Bank 2 Sensor 1 Low
- P0453 Evaporative Emission System Pressure Sensor/Switch A Circuit High Low
- P0459 Evaporative Emission System Purge Control Valve A Circuit High Low
- P0463 Fuel Level Sensor A Circuit High Input Low
- P0468 Evaporative Emission Purge Flow Sensor Circuit High Low
- P0473 Exhaust Pressure Sensor A Circuit High Stop driving Moderate
- P0478 Exhaust Pressure Control Valve A High Low
- P0490 Exhaust Gas Recirculation A Control Circuit High Moderate
- P0517 Battery Temperature Sensor Circuit High Low
- P0523 Engine Oil Pressure Sensor/Switch A High Moderate
- P0538 Air Conditioning Evaporator Temperature Sensor Circuit High Low
- P0553 Power Steering Pressure Sensor/Switch Circuit High Low
- P0558 Brake Booster Pressure Sensor Circuit High Input Moderate
- P0584 Cruise Control Vacuum Control Circuit High Low
- P0588 Cruise Control Vent Control Circuit High Low
- P0596 Cruise Control Servo Control Circuit High Low
- P0599 Thermostat Heater Control Circuit High Moderate
- P0629 Fuel Pump A Control Circuit High High
- P0637 Power Steering Control Circuit High Moderate
- P0690 Engine Control Module Power Relay Sense Circuit High High
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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