What Does P02D4 Mean?
The ECM has detected that Cylinder 5 fuel injector offset learning correction has reached its minimum allowable limit. The adaptive strategy is subtracting the maximum fuel from Cylinder 5, but the over-fueling exceeds the correction range. This is typically seen on V6, V8, or inline-5 engines and indicates Cylinder 5 is delivering more fuel than intended.
Common Causes
40%
Leaking or over-flowing Cylinder 5 fuel injector delivering excess fuel beyond the ECM adaptive correction window
25%
Incorrect or mismatched replacement injector installed in Cylinder 5 position with higher flow rating
20%
Bank 2 fuel rail pressure elevated from regulator malfunction causing disproportionate Cylinder 5 over-delivery
15%
Injector tip deposits on Cylinder 5 altering spray pattern and increasing delivered fuel volume
Diagnostic Steps
1
Step 1: Retrieve and compare all cylinder injector offset values. Confirm Cylinder 5 shows the most negative offset, indicating the ECM is subtracting the maximum fuel from that cylinder.
2
Step 2: Monitor per-cylinder fuel contribution and fuel trim data at idle and 2500 RPM to quantify the Cylinder 5 rich condition.
3
Step 3: Swap the Cylinder 5 injector with an adjacent cylinder on the same fuel rail. Clear adaptations and drive through a relearn cycle to isolate the injector versus position.
4
Step 4: On V-configuration engines, check Bank 2 fuel rail pressure independently if equipped with separate regulators. Compare to Bank 1 pressure to identify a bank-specific pressure issue.
5
Step 5: If the injector tests normal, perform a compression and leak-down test on Cylinder 5 to check for mechanical conditions affecting combustion that could bias the offset learning.
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
The ECM has detected that Cylinder 5 fuel injector offset learning correction has reached its minimum allowable limit. The adaptive strategy is subtracting the maximum fuel from Cylinder 5, but the over-fueling exceeds the correction range. This is typically seen on V6, V8, or inline-5 engines and i...
The most common cause of P02D4 (Cylinder 5 Fuel Injector Offset Learning At Min Limit) is: Leaking or over-flowing Cylinder 5 fuel injector delivering excess fuel beyond the ECM adaptive correction window
Typical repair costs for P02D4 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Over-fueling on Cylinder 5 increases unburned hydrocarbons reaching the catalytic converter, can cause catalyst overheating, and may wash cylinder walls reducing engine lubrication.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P02D4 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel Injection System
Difficulty
Type
Generic (SAE)
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