P0168
Fuel Temperature Too High
If your code reader dashboard displays the generic DTC error code P0168, your vehicle is currently experiencing an active failure related to "Fuel Temperature Too High". Proper system troubleshooting is required to safely clear this warning.
Driver's Summary
Storing code P0168 is your car's way of telling you something is wrong with the fuel temperature too high. On the road, this usually shows up as vapor lock symptoms, engine stalling when hot, check engine light. This is a moderate-severity fault — plan a repair shop visit within the week to keep it from escalating.
Symptoms
Vapor lock symptoms, engine stalling when hot, check engine light
Common Causes
- Low fuel level in tank (fuel is used to cool the pump)
- Faulty fuel cooler (if equipped)
- Failed fuel temperature sensor
- Fuel lines routed too close to exhaust
How to Fix
- 1 Keep fuel tank at least 1/4 full
- 2 Inspect and repair fuel cooler circuit
- 3 Replace fuel temperature sensor
- 4 Install heat shielding on fuel lines
Technical Explanation
The PCM triggers P0168 after its internal monitoring routine detects that a specific circuit or sensor has exceeded its acceptable operating range. The module measures the voltage return on the 5V reference circuit, comparing it to the expected signal envelope at current engine load and RPM. A deviation greater than the calibrated threshold — typically ±10% outside the normal operating window — flags the fault. Once confirmed, the code is stored as a permanent DTC and the MIL is activated. The freeze frame snapshot — recording RPM, load, coolant temperature, and fuel trim at fault detection — is also saved and is critical for accurate diagnosis.
Is It Safe to Drive?
You can drive short distances, but the symptoms — vapor lock symptoms, engine stalling when hot, check engine light — indicate the affected system is compromised. Leaving this unresolved will lead to progressively worse fuel economy and potential damage to components beyond the original fault.
Mechanic's Pro Tip
The most common mistake with P0168 is replacing the sensor without verifying the reference voltage and ground integrity first. Use a scan tool to monitor the sensor's live output; a truly failed sensor shows a stuck, flatlined reading — a sensor that fluctuates but reads slightly off usually indicates a wiring or vacuum issue, not a dead sensor. Always spray electrical contact cleaner on the connector pins before condemning the sensor.
Related Fault Codes
Frequently Asked Questions
What does OBD2 code P0168 mean?
OBD2 code P0168 refers to Fuel Temperature Too High. If your code reader dashboard displays the generic DTC error code P0168, your vehicle is currently experiencing an active failure related to "Fuel Temperature Too High". Proper system troubleshooting is required to safely clear this warning.
What are the most common symptoms of DTC P0168?
Drivers experiencing code P0168 typically report: Vapor lock symptoms, engine stalling when hot, check engine light.
Is it safe to drive with trouble code P0168 active?
You can drive short distances, but the symptoms — vapor lock symptoms, engine stalling when hot, check engine light — indicate the affected system is compromised. Leaving this unresolved will lead to progressively worse fuel economy and potential damage to components beyond the original fault.
How much does it cost to fix code P0168?
The estimated repair cost for P0168 ranges from $50 to $400 USD. Sensor replacement: $100 - $250; Heat shielding: $50 - $100
Sensor replacement: $100 - $250; Heat shielding: $50 - $100
Need Professional Diagnostic Assistance?
Always verify sensor signals and wiring integrity with an OBD2 scanner before purchasing replacement parts.
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