OBD-II Generic Error Code P0188: How to Fix It

Medium 30-60 minutes Medium Severity Verified June 2026
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Error Code
P0188
Brand
OBD-II Generic
Product Type
automotive
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
30-60 minutes
Error code P0188 indicates that the fuel temperature sensor 'B' is reporting a voltage that is too high, often due to a faulty sensor, wiring issues, or a short circuit. This can cause poor fuel economy, hard starting, or engine performance problems. Here's how to diagnose and fix it.
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Tools You'll Need

How to Fix Error Code P0188

  1. Check for Other Codes

  2. Inspect the Fuel Temperature Sensor Connector

    Ensure the engine is off and the key is removed before disconnecting any sensors.

  3. Test the Sensor Resistance

  4. Check for Short Circuits in Wiring

    Beware of moving engine parts or hot surfaces when accessing wiring.

  5. Replace the Fuel Temperature Sensor

    Work in a well-ventilated area; fuel vapors are flammable.

  6. Clear Codes and Test Drive

Parts You May Need

Fuel temperature sensor
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Fuel temperature sensor
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Fuel temperature sensor
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Fuel temperature sensor
Check Price on Amazon
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When to Call a Professional

If you have tested the sensor and wiring but the code persists, or if you are uncomfortable working with fuel system components, consult a professional mechanic. Also, if the problem is intermittent and you cannot replicate it, a professional diagnosis may be needed.

Frequently Asked Questions

Can I drive with error code P0188?
It is not recommended to drive long distances with this code, as it can affect engine performance and fuel efficiency. You may experience hard starting or stalling.
What causes P0188?
Common causes include a faulty fuel temperature sensor, damaged wiring or connectors, a short circuit, or a problem with the engine control module (ECM).
How much does it cost to fix P0188?
If you DIY, the sensor typically costs $20-$80. Professional repair may range from $100-$200 including labor.
Is P0188 the same as P0187?
No, P0187 is for Fuel Temperature Sensor B circuit low input, while P0188 is for high input. They indicate opposite voltage issues.
Can a bad fuel temperature sensor cause a check engine light?
Yes, it will usually trigger the check engine light and store code P0188.

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