P029C - Cylinder 1 – Fuel Injector Leaking
Last updated:
System
Powertrain (Engine & Gearbox)
Related Fault Codes
Technical Description
P029C is a diagnostic trouble code (DTC) that indicates the Engine Control Unit (ECU) has detected a leaking fuel injector for Cylinder 1. The ECU monitors fuel trim values and oxygen sensor feedback to determine if a specific cylinder is running too rich. If the injector fails to close completely or has a compromised internal seal, it will allow excess fuel into the combustion chamber, causing a rich condition that the ECU cannot compensate for through standard pulse-width modulation.
Possible Causes
Faulty fuel injector for cylinder 1 (internal mechanical leak or debris)
Wiring or connector issue (short to ground on the control circuit)
Contaminated fuel causing deposits within the injector nozzle
Faulty fuel pressure regulator or damaged ECU injector driver
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.
Do you also have
other fault codes?
See how P029C connects with your other fault codes. Our advanced analysis tool identifies causal relationships and root causes directly.