What does fuel trim malfunction mean?
Diagnostic Trouble Code (DTC) P0170 stands for “Fuel Trim Malfunction (Bank 1).” Fuel trim is the adjustment made by the PCM to the engine’s air-fuel mixture. The P0170 code indicates that the fuel trims have reached an abnormally low or abnormally high value for a specified amount of time.
What does fuel trim code mean?
The P0170 code means that the powertrain control module is detecting a fuel trim that is outside the range of specification set by the vehicle’s manufacturer. This can mean a negative fuel trim or a positive fuel trim has been detected. This action carried out by the powertrain control module is called a fuel trim.
How do you reset fuel trims?
To perform a PCM reset…
- Bring car up to normal operating temp.
- Turn ignition off.
- Remove ECM main fuse.
- Turn ignition to “on”, do not start.
- Wait for system check to complete, numerous errors will be detected.
- Turn ignition off.
- Replace fuse.
- Turn ignition to “on” and wait for system check.
What should my long term fuel trim idle?
If long-term fuel trim (LTFT) for bank 1 is 25% at idle, but corrects to 4% at 1,500 and 2,500 rpm, focus on factors that cause a lean condition at idle, such as a vacuum leak.
What is the diagnostic code for fuel trim malfunction?
P0173 is a diagnostic trouble code (DTC) for “Fuel Trim Malfunction (Bank 2)”. This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation.
What does it mean when fuel trim data is failing?
In this example, the fuel trim data was failing in both banks and every operating range—idle speed, light load, moderate load and heavy load—which means the lean condition was present in all driving conditions. What are your thoughts about an intake air leak now?
What should bank 1 fuel trim be at idle?
If long-term fuel trim (LTFT) for bank 1 is 25% at idle, but corrects to 4% at 1,500 and 2,500 rpm, focus on factors that cause a lean condition at idle, such as a vacuum leak.
How does fuel trim work on a check engine light?
When diagnosing a check-engine light or drivability issue, you can learn a lot by looking at fuel trim data on a scan tool. Fuel trim can be affected by just about anything between the air filter and the muffler, including sensors, injectors, ignition, EGR, the engine’s mechanical condition and even the crankcase ventilation system.