Powertrain (Engine & Gearbox)Standard EOBD

P029F - Cylinder 11 Injector - Trim Offset at Maximum Limit

Q: What are the symptoms of fault code P029F?

• Check engine light (MIL) illuminated • Rough idling or misfiring • Noticeable loss of engine power • Decreased fuel economy • Vehicle may enter 'Limp mode' • Failed emission test

Q: What causes fault code P029F?

• Most likely: Clogged or faulty fuel injector (cylinder 11) • Likely: Vacuum leak specifically at the intake manifold runner for cylinder 11 • Possible: Ignition system fault (spark plug/coil) causing incomplete combustion/false lean reading • Rare: Internal engine mechanical issue (low compression in cylinder 11) • Rare: Wiring issue leading to high resistance in the injector circuit

Q: How do you fix fault code P029F?

STEP 1: Visually inspect injector 11 wiring harness and connector for corrosion or damage. Check for vacuum leaks near the intake port. STEP 2: Measure the injector resistance (Ohms). Typical values are 11-14 Ohms (verify with service manual). Check for 12V supply with a multimeter. STEP 3: Use an oscilloscope to verify the injector pulse width/duty cycle signals from the ECM. STEP 4: Perform a fuel pressure test and an injector balance test. Consider swapping the injector to another cylinder to see if the fault follows the component. STEP 5: If the injector is confirmed faulty, replace it and reset fuel trim adaptations using a scan tool.

Last updated:1 February 2026

Related:Fuel Injector Cylinder 11, Engine Control Unit (ECU/ECM), Oxygen Sensor (O2), Insugspackning, Spark Plug

System

Powertrain (Engine & Gearbox)

Related Fault Codes

P0200

Injector Circuit Malfunction

P0201

Cylinder 1 Injector Circuit Open

P0202

Injector Circuit - Cylinder 2 - Malfunction

P0203

Injector Circuit - Cylinder 3

Technical Description

Diagnostic Trouble Code (DTC) P029F occurs when the Engine Control Module (ECM) detects that the fuel trim for cylinder 11 has reached its maximum enrichment limit. The ECM is attempting to compensate for a perceived lean condition by increasing the injector pulse width, but the correction factor has exceeded the calibrated threshold. This monitoring is typically performed using wide-band oxygen sensors and crankshaft speed fluctuation analysis to isolate issues to a specific cylinder.

Possible Causes

Clogged or faulty fuel injector (cylinder 11)

Vacuum leak specifically at the intake manifold runner for cylinder 11

Ignition system fault (spark plug/coil) causing incomplete combustion/false lean reading

Internal engine mechanical issue (low compression in cylinder 11)

Wiring issue leading to high resistance in the injector circuit

Symptoms

Check engine light (MIL) illuminated

Rough idling or misfiring

Noticeable loss of engine power

Decreased fuel economy

Vehicle may enter 'Limp mode'

Failed emission test

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P029F - Cylinder 11 Injector - Trim Offset at Maximum Limit

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P029F - Cylinder 11 Injector - Trim Offset at Maximum Limit

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