Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's computer thinks the engine isn't running smoothly and is trying too hard to fix it.
This code indicates that the engine control module (ECM) has detected an excessive correction in the fuel injection system to maintain smooth engine operation.
The P1278 code is triggered when the ECM detects that the correction quantity for engine smoothness control is too high. This means the ECM is making significant adjustments to the fuel injection to try and smooth out the engine operation, which could be due to a misfire, imbalance, or other issues affecting engine performance.
• Rough engine idle
• Decreased fuel efficiency
• Check Engine Light on
• Faulty fuel injector
• Engine misfire
• Air intake leak
ECM: Engine Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Check for other error codes
• Inspect fuel injectors for clogs or damage
• Perform a compression test on the engine
• Replace faulty fuel injectors
• Repair any air intake leaks
• Fix any detected engine misfires
• OBD-II scanner
• Fuel injector tester
• Compression tester
$200 - $600
Moderate
• BMW 3 Series
• Audi A4
• Volkswagen Passat
• Regular engine maintenance
• Use high-quality fuel
• Check and replace air filters regularly
Engine Performance
• Avoid driving aggressively until the issue is resolved
• Schedule a repair as soon as possible
Check with your vehicle manufacturer for warranty coverage on engine components.
This code has been associated with issues in vehicles with direct fuel injection systems, particularly in European models.
Moderate – Should be addressed soon to prevent further engine damage.
Driving with this code may lead to increased emissions and potential engine damage. Address promptly.
• Engine at operating temperature
• Vehicle in idle or low-speed operation
The fuel injectors are typically located on the engine's intake manifold.
Q: Can I drive my car with a P1278 code?
A: It's not recommended as it might cause further engine damage or increased emissions.
Q: How can I prevent this code from appearing?
A: Regular maintenance and using high-quality fuel can help prevent this issue.
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Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
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Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.