P3400 on Acura
Cylinder Deactivation System Bank 1
P3400 on Acura vehicles indicates cylinder deactivation system bank 1. Au7o has documented this code across 1 Acura model — most commonly on MDX. This code indicates the engine control module detected a fault in the cylinder deactivation (variable displacement) system on bank 1, the side of the engine containing cylinder number one. Cylinder deactivation closes the valves and cuts fuel to certain cylinders under light load to save fuel, using oil-pressure-operated control solenoids. When the system can't operate correctly, the module sets this code; you may notice reduced fuel economy, a slight performance change, or a warning light. The most common trigger is low oil level or poor oil pressure. Typical repair costs on Acura range from $400 to $3,500, depending on the specific model and root cause.
Common Causes of P3400
- •Low engine oil level or low oil pressure
- •Clogged or dirty oil passages/lifters
- •Faulty active fuel management / cylinder deactivation solenoid
- •Failed deactivating lifter or collapsed lifter
- •Wiring or connector fault in the solenoid circuit
- •Sludge from missed oil changes
- •Faulty oil pressure sensor
P3400 on Acura by Model
Acura MDX(1 issue)
- VCM-Related Oil Consumption, Spark Plug Fouling and Motor Mount Failure (J37 VCM Engine)2010-2013
Variable Cylinder Management (VCM) on the J37A1 3.7L V6 deactivates one bank of three cylinders under light load. Over time the deactivated cylinders burn oil past the rings, fouling plugs, and the constant 6-3-6 cylinder transition prematurely wears the hydraulic Active Control Engine Mounts (front + rear). Subject of a class-action settlement (Soto v. American Honda) covering 2010-2013 MDX, 2011-2012 RL, 2009-2014 TL and 2010-2013 ZDX with the J37 engine.
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View P3400 across all makes →Frequently Asked Questions
What does P3400 mean on Acura?▼
P3400 stands for "Cylinder Deactivation System Bank 1." This code indicates the engine control module detected a fault in the cylinder deactivation (variable displacement) system on bank 1, the side of the engine containing cylinder number one. Cylinder deactivation closes the valves and cuts fuel to certain cylinders under light load to save fuel, using oil-pressure-operated control solenoids. When the system can't operate correctly, the module sets this code; you may notice reduced fuel economy, a slight performance change, or a warning light. The most common trigger is low oil level or poor oil pressure. On Acura specifically, this code is documented across 1 model.
What causes P3400 on Acura vehicles?▼
Common causes on Acura: Low engine oil level or low oil pressure, Clogged or dirty oil passages/lifters, Faulty active fuel management / cylinder deactivation solenoid, Failed deactivating lifter or collapsed lifter, Wiring or connector fault in the solenoid circuit. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P3400 on a Acura?▼
Repair costs on Acura range from $400 to $3,500, depending on the specific model and root cause.
Which Acura models have P3400 documented?▼
Au7o has documented P3400 on 1 Acura model: MDX.