108F01
Moderate108F01 — Suspected Intake Air Leak
Description
What the Code Means
108F01 flags a suspected leak in the intake system — the section between the exhaust turbocharger and the intake valves. Unmetered air enters the engine through a leaking connection: the DME reads air mass from the sensors upstream of the leak, but more air actually reaches the cylinders. The fuel-air mixture runs lean, and the control unit logs a mismatch between calculated and actual values.
Symptoms
Symptoms
- Drivetrain malfunction warning on the instrument cluster.
- Possible loss of engine power.
Causes and fixes
Diagnosis and Repair
Step 1. Inspect the Intake Tract
Check the intake hoses, gaskets, and all connections between the turbocharger and the intake valves for cracks, loose clamps, and poorly seated gaskets.
Step 2. Smoke Test
If a visual inspection turns up nothing, run a smoke test on the intake system — smoke will pinpoint the leak you couldn't spot in the static inspection.
After sealing the leak, clear the code and check whether it returns on subsequent drives.
Possible secondary damage
Secondary Issues
- The main consequence of ignoring the leak is reduced fuel economy.
- Catalytic converter damage is possible, which leads to a more expensive repair.
- Otherwise the car may remain drivable, but don't put off diagnosis.