Fuel Trim Cylinder Balance -- Bank 1 (GM)
What does P1174 mean?
The P1174 code means the vehicle's onboard diagnostic system has detected: Fuel Trim Cylinder Balance -- Bank 1 (GM). This is a moderate severity code.
Common Symptoms
- Check Engine Light on
- Rough idle or misfire
- Poor fuel economy
- Engine vibration at idle
- Hesitation during acceleration
Probable Causes (Ranked by Likelihood)
- Dirty or clogged fuel injector on one bank 1 cylinder Very High
- Intake manifold gasket leak on bank 1 High
- Worn spark plugs or ignition coils on bank 1 Moderate
- Low compression on one bank 1 cylinder Moderate
- Carbon buildup on intake valves (GDI engines) Low
Step-by-Step Diagnostic Procedure
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Check freeze frame data to identify which cylinder is at fault
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Perform a fuel injector balance test on bank 1
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Check for vacuum leaks specific to bank 1 cylinders
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Inspect spark plugs and ignition coils on bank 1
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Perform a compression test on bank 1 cylinders if other tests are inconclusive
Frequently Asked Questions
Can I drive with code P1174?
You can drive short distances. This code indicates a single cylinder on bank 1 is not getting the correct fuel mixture. The engine may misfire at idle but otherwise drive acceptably.
What causes P1174 on GM vehicles?
GM uses cylinder-level fuel trim monitoring. P1174 means one cylinder on bank 1 needs significantly more or less fuel than the others. A dirty injector or intake leak on that cylinder is the most likely cause.
Will fuel injector cleaner help?
Quality fuel injector cleaner added to the fuel tank may help if the injector is only partially clogged. For severely clogged injectors, professional ultrasonic cleaning or injector replacement may be needed.