What Does P02A5 Mean?
The ECM has detected that the fuel injector on cylinder 3 is leaking fuel into the combustion chamber when the injector should be fully closed. Individual cylinder fuel trim analysis shows cylinder 3 consistently requires maximum negative fuel correction due to excessive fuel delivery. The driver may notice rough idle, black exhaust smoke, fuel smell, a carbon-fouled spark plug on cylinder 3, and potentially hard starting if significant fuel puddles in the cylinder.
Common Causes
40%
Worn or damaged cylinder 3 injector pintle or valve seat allowing fuel seepage when de-energized
25%
Foreign debris lodged in the injector tip preventing complete closure
15%
Weakened or broken injector return spring unable to close the valve against fuel pressure
12%
Excessive fuel rail pressure pushing fuel past a marginally sealing injector
8%
ECM driver circuit keeping the injector partially energized when it should be off
Diagnostic Steps
1
Perform a fuel injector leak-down test: with the engine off and fuel rail pressurized to operating pressure, remove the cylinder 3 spark plug and watch for fuel dripping into the bore over 10-15 minutes. Any more than one drop per minute is excessive.
2
Monitor cylinder 3 individual fuel trim on the scan tool; it should be at the maximum negative correction limit, confirming over-fueling.
3
Remove and compare the cylinder 3 spark plug condition against other cylinders; it should be noticeably darker and wetter if the injector is leaking.
4
Remove the cylinder 3 injector and bench-test for static leak rate (no electrical energy applied); any measurable fuel flow with the injector off confirms the leak.
5
Measure fuel rail pressure with a gauge and verify it is within the manufacturer's specification; reduce excessive pressure if found.
Estimated Repair Cost
$100 - $500
Parts + labor, varies by vehicle and location
The ECM has detected that the fuel injector on cylinder 3 is leaking fuel into the combustion chamber when the injector should be fully closed. Individual cylinder fuel trim analysis shows cylinder 3 consistently requires maximum negative fuel correction due to excessive fuel delivery. The driver ma...
The most common cause of P02A5 (Cylinder 3 - Injector Leaking) is: Worn or damaged cylinder 3 injector pintle or valve seat allowing fuel seepage when de-energized
Typical repair costs for P02A5 range from $100 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A leaking injector is a fire hazard and can cause hydro-lock if enough fuel accumulates in the cylinder while the engine is off. Fuel washing the cylinder wall causes accelerated ring and bore wear. Do not leave the vehicle sitting for long periods and repair as soon as possible.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P02A5 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel Injection System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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