P0189
Fix within a few daysFuel Temperature Sensor "B" Circuit Intermittent/Erratic
Code P0189 means your fuel temperature sensor "B" is sending erratic signals. Common causes: Faulty sensor (70%), wiring issues (25%). Drivability: Yes, for short trips only. Repair cost: $50-$200 DIY, $150-$500 professional.
Can I Drive With P0189?
Yes, for short trips only
Essential trips under 10 miles, avoid highways and heavy acceleration. Fix within a few days.
Stop driving immediately if: Flashing CEL, significant power loss, strong fuel smell, or engine stalling.
Symptoms of P0189
- 1Check Engine Light is on
- 2Hard starting, especially when the engine is cold or hot
- 3Reduced fuel economy
- 4Rough idle or poor engine performance
- 5Engine may hesitate or stumble during acceleration
Common Causes of P0189
Parts most likely causing this code, ranked by probability
The sensor itself is failing internally, sending inconsistent or jumpy readings to the engine computer.
70% of P0189 cases are fixed by replacing this part
Damaged, corroded, or loose wires and connectors can cause intermittent signals from the sensor.
25% of P0189 cases are fixed by repairing wiring or connectors
A faulty engine computer can misinterpret the sensor's signal, though this is a rare cause.
5% of P0189 cases are fixed by replacing the ECM/PCM
Check These First (Before Buying Parts)
- Visually inspect the wiring harness and connector leading to the fuel temperature sensor "B" for any signs of damage, fraying, or corrosion. Ensure the connector is fully seated.
How to Diagnose P0189
- 1Visually inspect the fuel temperature sensor "B" wiring and connector for damage, corrosion, or loose connections.
- 2Using a scan tool, monitor the live data for the fuel temperature sensor "B" reading; look for erratic or frozen values.
- 3Disconnect the sensor and test its resistance with a multimeter, comparing readings to factory specifications at various temperatures if possible.
- 4Check for proper voltage supply and ground at the sensor connector.
P0189 on Popular Vehicles
Toyota Camry
2007-2024For Toyota Camry models, the fuel temperature sensor "B" is typically part of the fuel pump assembly located inside the fuel tank. Access requires removing the rear seat and opening an access panel, or dropping the fuel tank. The causes for P0189 are consistent across models.
70% fixed by replacing the sensor
Honda Accord
2003-2024On Honda Accord vehicles, the fuel temperature sensor "B" is usually integrated into the fuel pump module within the fuel tank. Diagnosis for P0189 involves checking the electrical circuit first, then the sensor. Causes are generally the same as other vehicles.
70% fixed by replacing the sensor
Ford F-150
2004-2024For Ford F-150 trucks, the fuel temperature sensor "B" is commonly found within the fuel pump module inside the fuel tank. Repairing P0189 often means dropping the fuel tank to access and replace the sensor or the entire fuel pump module if the sensor is not separately serviceable. Wiring issues are also a factor.
70% fixed by replacing the sensor
Frequently Asked Questions
What does P0189 mean?
P0189 indicates that the engine computer has detected an intermittent or erratic signal from the fuel temperature sensor "B" circuit. This sensor helps the computer adjust fuel delivery based on fuel temperature.
Can I drive with P0189?
Yes, you can drive for short trips, but you should fix this within a few days. The engine computer will use a default value for fuel temperature, which can lead to poor fuel economy and reduced performance. Prolonged driving with incorrect fuel mixture can cause other issues.
Will P0189 clear itself?
No, P0189 will not clear itself. The underlying issue, whether it's a faulty sensor or wiring problem, needs to be diagnosed and repaired. Once fixed, the code will clear after several drive cycles or can be manually cleared with a scan tool.
How do I fix P0189 myself?
Start by inspecting the wiring and connector for the fuel temperature sensor "B" for any visible damage or corrosion. If the wiring is good, you will likely need to replace the fuel temperature sensor "B" itself. Access to the sensor varies by vehicle; it can be on the fuel rail or inside the fuel tank.
How much does it cost to fix P0189?
A DIY fix for P0189 typically costs $50-$200 for the sensor part. If you take it to a shop, expect to pay $150-$500, which includes parts and labor, depending on the sensor's location and ease of access.
P0189 keeps coming back - why?
If P0189 keeps returning, it usually means the initial diagnosis missed something. Common reasons include a faulty wiring harness that was not fully repaired, a poor connection at the sensor or ECM, or a rare issue with the engine computer itself. Ensure all connections are clean and secure.
Will P0189 fail emissions/smog test?
Yes, P0189 will cause your vehicle to fail an emissions or smog test. The Check Engine Light being on is an automatic failure in most jurisdictions, and an erratic fuel temperature reading can directly impact the vehicle's emissions output.
What's the difference between P0189 and P0183?
P0189 indicates an 'intermittent/erratic' signal from the fuel temperature sensor "B", meaning the signal is inconsistent or jumping. P0183 indicates a 'high input' from the same sensor, meaning the voltage signal is continuously too high, suggesting an open circuit or short to voltage.
P0189 on Ford F-150?
On a Ford F-150, P0189 points to the fuel temperature sensor "B". This sensor is often integrated into the fuel pump assembly inside the fuel tank on many models. Diagnosis involves checking the wiring and then the sensor itself, which may require dropping the fuel tank for access.
Questions to Ask Your Mechanic
Did you check the live data for the fuel temperature sensor "B" for erratic readings?
Good answer: Yes, I monitored the sensor's output and saw it jumping inconsistently, confirming an erratic signal.
What did you find when you inspected the wiring and connector for the fuel temperature sensor "B"?
Good answer: I checked the wiring for any breaks or corrosion and confirmed the connector was secure and clean. All looked good, so the issue is likely internal to the sensor.
Repair Cost Estimate
DIY Repair
Parts only
$50-$200
Shop Repair
Parts + labor
$150-$500
Save $100-$300 by doing it yourself
Difficulty
intermediate
Time
1-3 hours
Intermediate - Requires a scan tool for diagnosis and potentially specialized tools or knowledge for accessing the sensor, especially if it's in the fuel tank.
Cost of Waiting
Ignoring P0189 leads to incorrect fuel mixture, causing reduced fuel economy and potentially rough running. Over time, this can increase wear on engine components and lead to more expensive repairs if the engine runs too rich or too lean.
While You're In There...
If the fuel temperature sensor is located within the fuel tank and requires dropping the tank, it makes sense to replace the fuel filter (if accessible) as it's a common maintenance item and the labor is already being performed.
If the fuel temperature sensor is integrated into the fuel pump assembly and cannot be replaced separately, or if the vehicle has high mileage, replacing the entire assembly prevents future fuel delivery issues and saves on repeat labor.
Tools You'll Need
- OBD-II Scan Tool with live data capability
- Multimeter
- Basic hand tools (sockets, wrenches)
- Fuel line disconnect tools (if sensor is on fuel rail)
- Jack and jack stands (if dropping fuel tank)
P0189 is a common sensor code. Most repairs involve replacing the fuel temperature sensor, which is a straightforward fix that restores proper engine function and fuel economy.
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Your Next Steps
Step 1: Visually inspect the wiring and connector for the fuel temperature sensor "B". Look for any obvious damage, corrosion, or loose connections. Repair as needed.
Step 2: If the wiring looks good, use an OBD-II scan tool to monitor the live data for the fuel temperature sensor "B". Look for erratic, frozen, or implausible readings. If the readings are clearly bad, the sensor is likely faulty.
Step 3: If the sensor is suspected, disconnect it and test its resistance with a multimeter. Compare your readings to the vehicle's service manual specifications. If the resistance is out of spec, replace the fuel temperature sensor "B".