Symptom Guide
Check engine light on Symptom Hub
A check-engine light is a graph entry point into code pages, symptom-specific diagnosis, and the exact repair categories most often associated with those failures.
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Related Resources
Repair guides, wiring diagrams, and other pages related to this symptom.
Likely Repair Categories
Browse →Open the repair category that best matches check engine light complaints.
Open the repair category that best matches check engine light complaints.
Open the repair category that best matches check engine light complaints.
Open the repair category that best matches check engine light complaints.
Open the repair category that best matches check engine light complaints.
Codes Often Seen With This Symptom
Browse →The ECM detected a fault in the exhaust camshaft VVT solenoid circuit on bank 1. This solenoid controls exhaust valve timing for optimal performance and emissions.
The oxygen sensor heater circuit on the upstream (pre-cat) sensor of bank 1 has a fault. The heater gets the O2 sensor to operating temperature quickly for proper fuel trim.
The O2 sensor heater circuit voltage is lower than expected on the upstream bank 1 sensor. Usually means an open circuit in the heater element.
General fault with the upstream O2 sensor on bank 1. This sensor monitors exhaust oxygen to control fuel mixture.
The upstream O2 sensor on bank 1 is stuck at a low voltage, indicating a lean exhaust condition. Could be the sensor or an actual lean condition.
The upstream O2 sensor on bank 1 is responding too slowly to changes in exhaust oxygen content. Known as a lazy O2 sensor.
The upstream O2 sensor on bank 1 shows no switching activity. The sensor may be dead or disconnected.
The heater in the upstream O2 sensor on bank 1 is not working properly. The heater brings the sensor to operating temperature quickly.
Exact Vehicle Pages To Inspect
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Open an exact repair page tied to this symptom cluster.
Open an exact repair page tied to this symptom cluster.
Open an exact repair page tied to this symptom cluster.
Related Trouble Codes
These check engine light codes are often associated with this symptom.
Emissions Code
P0030: HO2S Heater Control Circuit (Bank 1, Sensor 1)
Emissions Code
P0031: HO2S Heater Control Circuit Low (Bank 1, Sensor 1)
Emissions Code
P0130: O2 Sensor Circuit (Bank 1, Sensor 1)
Emissions Code
P0131: O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1)
Emissions Code
P0133: O2 Sensor Circuit Slow Response (Bank 1, Sensor 1)
Emissions Code
P0134: O2 Sensor Circuit No Activity Detected (Bank 1, Sensor 1)
Repairs That May Fix This
These repair guides are commonly needed when you experience this symptom.