- Faulty Oxygen Sensor: The oxygen sensor monitors the amount of oxygen in the exhaust gases to ensure proper fuel-to-air ratio. A faulty oxygen sensor can cause the check engine light to illuminate and affect the speedometer's functionality by providing incorrect data to the engine control unit (ECU), leading to incorrect fuel mixture calculations and potentially causing transmission shifting issues or speedometer malfunction.
- Transmission Issues: Problems with the transmission, such as slipping gears, faulty shift solenoids, or transmission fluid issues, can trigger the check engine light and impact the speedometer.
- ECU Malfunction: In some cases, a malfunctioning engine control unit (ECU) can cause various electrical issues, including the check engine light and speedometer malfunction.
Speedometer Not Working:
- Speed Sensor Failure: The speed sensor, typically located near the transmission or wheels, provides the vehicle's speed information to the speedometer. If this sensor fails or its wiring is faulty, the speedometer may not receive accurate speed readings and malfunction.
- Faulty Instrument Cluster: The instrument cluster, which houses the speedometer, may have an internal fault or loose electrical connections, causing the speedometer not to function properly.
To accurately diagnose the issue and determine the specific cause of the check engine light and speedometer malfunction, it's essential to have the vehicle inspected by a qualified mechanic or technician who can perform diagnostic tests and pinpoint the exact problem.
