This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.
P1174 is an OBD-II Code that refers to Fuel Pump A Low Flow/Performance
A P1174 code is a diagnostic trouble code related to that occurs when the PCM/ECM receives a signal from the fuel cylinder balance diagnostic that the check for fuel mixture is in imbalance between a rich and lean cylinder. The catalyst's oxygen sensor (HO2S) signal is monitored ahead of the catalytic converter. As a result, it calculates the voltage that has built up over a set length of time.
If the pressure isn't within the required parameters, the P1174 code will be set if several samples of the accumulated voltage turn out to have inconsistencies higher than the expected value.
Common causes for this code include:
- The fuel injector(s) may be clogged
- An oxygen sensor may have malfunctioned
- It is possible that the motor has experienced other mechanical problems
The symptoms of a P1174 code are:
- Illuminated Check Engine Light
- Other Related Oxygen DTCs are stored
- Fuel efficiency issues
To diagnose a P1174 DTC code, a technician would:
- Scan for codes in the ECM and look at the freeze frame data for failure.
- Visually inspect the fuel system for any defects.
- Check the engine compression, ignition timing and idle quality.
- Test the fuel pressure and volume.
- Check the oxygen sensor(s) and wiring.
- Check the electrical connectors and grounds.
- If everything checks out, then it is likely that there is a mechanical issue with the engine.
The following are some of the most common mistakes that a technician may make when diagnosing a P1174 code:
- Not thoroughly inspecting all the wiring and connectors for damage.
- Not checking the fuel pressure and volume.
- Not properly diagnosing an oxygen sensor issue.
- Not properly checking the engine compression, ignition timing or idle quality.
How serious is this?
A P1174 code is a serious code and should be addressed as soon as possible. If left untreated, it may cause further damage to the engine and lead to a failed emission test.
What repairs can fix the code?
The following are solutions that may fix this problem:
- Repair or replace any wiring that is damaged
- Replace any clogged fuel injectors
- Replace any malfunctioning oxygen sensors
- Repair or replace any damaged engine components
- Perform a tune-up including adjusting the ignition timing and idle quality
A P1174 is related to and may be accompanied by the following codes:
P0304 – Cylinder 4 Misfire Detected
P0300 – Random/Multiple Cylinder Misfire Detected
In conclusion, the P1174 code is a diagnostic trouble code that refers to a problem with the fuel pump. The code is set when the PCM/ECM receives a signal from the fuel cylinder balance diagnostic that the check for fuel mixture is in imbalance between a rich and lean cylinder. There are several possible causes for this code, and it should be addressed as soon as possible to prevent further damage to the engine.