Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
Your car has a part that helps it stay running when you're not pressing the gas. This part isn't working right on one side of the engine.
The code P158B indicates a malfunction in the idle speed control valve on Bank 1, which helps regulate the engine's idle speed.
The P158B code is triggered when the Engine Control Module (ECM) detects an issue with the internal idle speed control valve on Bank 1. This valve is responsible for maintaining the engine's idle speed by adjusting the amount of air entering the engine. A failure in this system can lead to poor idle performance.
• Engine stalls at idle
• Rough idle
• Check Engine Light is on
• Faulty idle speed control valve
• Wiring issues or poor electrical connections
• Faulty ECM
ECM: Engine Control Module
Idle Speed Control Valve: A component that regulates engine idle speed
• Use an OBD-II scanner to confirm the code.
• Inspect the idle speed control valve and its wiring for damage.
• Test the electrical connections to the valve.
• Replace the idle speed control valve.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Toyota Camry
• Honda Accord
• Ford Focus
• Regularly clean the throttle body and idle control valve.
• Perform routine maintenance checks.
• Ensure electrical connections are secure.
Engine Performance
• Avoid driving with this issue for long periods.
• Seek professional diagnosis and repair.
Check with your vehicle manufacturer as some components may be covered under warranty.
This code has been reported in vehicles with higher mileage, often due to wear and tear on the idle control system.
Moderate – While the vehicle may still be drivable, it can lead to stalling and should be addressed soon.
Driving with a malfunctioning idle speed control can lead to unsafe driving conditions.
• Engine at operating temperature
• Vehicle in idle state
The idle speed control valve is typically located on the throttle body of the engine.
Q: Can I drive with a P158B code?
A: It's not recommended as it can lead to stalling and unsafe driving conditions.
Q: How do I clear a P158B code?
A: After repairs, use an OBD-II scanner to clear the code. If the problem persists, further diagnosis is needed.
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