P02A4 - Cylinder 3 Injector Restricted
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System
Powertrain (Engine & Gearbox)
Related Fault Codes
Technical Description
P02A4 is set when the Engine Control Unit (ECU) detects that the fuel injector for cylinder 3 has reached its lower adaptive learning limit. The ECU attempts to compensate for a rich condition or mechanical deviation by reducing injector pulse width. When the compensation value hits the minimum threshold and the desired lambda/combustion target is still not achieved, the fault code is triggered. This typically suggests a leaking injector or a cylinder balance issue where the ECU is trying to lean out the mixture beyond its calibrated window.
Possible Causes
Defective or leaking fuel injector (Cylinder 3)
Clogged or restricted injector flow (contamination)
High resistance in wiring or harness connector
Compression loss or valve issues on cylinder 3
Symptoms
Recommended Solution
Workflow
Mechanic's Tip
Before replacing expensive components, always double-check wiring and connections. 80% of all sensor faults are actually due to corroded contacts or broken wires.
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