What Does P02D1 Mean?
The ECM has detected that Cylinder 3 fuel injector offset learning correction has reached its maximum allowable limit. The PCM is adding the maximum amount of fuel to Cylinder 3 but cannot sufficiently compensate for under-fueling. Cylinder 3 injector is delivering significantly less fuel than commanded, suggesting a clogged injector, weak coil, or mechanical issue restricting fuel delivery.
Common Causes
40%
Partially clogged or restricted Cylinder 3 fuel injector reducing flow rate below ECM adaptive correction capability
25%
Failing Cylinder 3 injector solenoid coil with increased resistance reducing pintle opening and fuel volume
20%
Low fuel system pressure from a degraded fuel pump or restricted fuel filter affecting Cylinder 3 delivery most
15%
Vacuum leak near Cylinder 3 intake runner causing unmetered air entry and a localized lean condition
Diagnostic Steps
1
Step 1: Review injector offset learning values for all cylinders. A significantly positive offset on Cylinder 3 confirms under-fueling relative to other cylinders.
2
Step 2: Perform an injector balance test or flow bench test comparing Cylinder 3 injector output to the other injectors. Flow should be within 5% of the set average.
3
Step 3: Swap Cylinder 3 injector with an adjacent cylinder, clear adaptations, and drive through a relearn cycle. If the lean condition follows the injector, replace or ultrasonically clean it.
4
Step 4: Use a smoke machine to check for vacuum leaks around Cylinder 3 intake port, runner gasket, and any adjacent vacuum connections. Even a small leak can create a significant lean bias.
5
Step 5: Measure fuel rail pressure at idle and under wide-open throttle. Confirm the fuel pump maintains adequate pressure and volume under all operating conditions.
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
The ECM has detected that Cylinder 3 fuel injector offset learning correction has reached its maximum allowable limit. The PCM is adding the maximum amount of fuel to Cylinder 3 but cannot sufficiently compensate for under-fueling. Cylinder 3 injector is delivering significantly less fuel than comma...
The most common cause of P02D1 (Cylinder 3 Fuel Injector Offset Learning At Max Limit) is: Partially clogged or restricted Cylinder 3 fuel injector reducing flow rate below ECM adaptive correction capability
Typical repair costs for P02D1 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Under-fueling causes lean misfires that elevate exhaust gas temperatures, potentially damaging the catalytic converter and causing noticeable hesitation or rough running.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P02D1 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel Injection System
Difficulty
Type
Generic (SAE)
Recommended Tools
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