Fuel Temperature Sensor B Circuit Intermittent
The P0188 code means the vehicle's onboard diagnostic system has detected: Fuel Temperature Sensor B Circuit Intermittent. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $60 - $300 (parts and labor)
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Common Symptoms
- Check Engine Light on intermittently
- Fuel temperature readings jump erratically on scan tool
- Occasional engine performance issues
- Code may clear and return
Probable Causes (Ranked by Likelihood)
- Loose or corroded connector at fuel temp sensor B Very High
- Intermittent break in sensor wiring High
- Failing sensor with intermittent internal connection Moderate
- Vibration-induced wiring fault Low
Step-by-Step Diagnostic Procedure
-
Monitor fuel temp sensor B on scan tool while wiggling the connector and wiring. Watch for sudden reading changes.
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Inspect connector pins for corrosion, looseness, or contamination.
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Check wiring for cracked insulation or breaks, especially at flex points.
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If wiggle test causes readings to jump, isolate the fault to connector, wiring, or sensor.
Frequently Asked Questions
What does intermittent mean for P0188?
The fault comes and goes. The sensor circuit sometimes reads normally and sometimes fails, typically from a loose connection or cracked wire.
How do I find an intermittent wiring fault?
Use the wiggle test: monitor the sensor reading on a scan tool while gently wiggling the connector, harness, and sensor. The point where the reading jumps is the fault location.
Can vibration cause P0188?
Yes, engine and road vibration can cause intermittent connections in worn connectors or cracked wires, especially on diesel trucks with higher vibration levels.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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