EN

Severity: Low Code type: Generic (all makes)

P0081 Code: Intake Valve Control Solenoid Circuit (Bank 2)

Electrical fault in the bank 2 intake cam solenoid on a V6 or V8; only one cylinder bank loses cam timing.

At a glance

Severity: 2/5 – Low2/5

Severity: Low

Meaning
Intake Valve Control Solenoid Circuit (Bank 2)
System
Fuel & Air Metering · Powertrain
Safe to drive?
Yes, short term
Typical repair cost
$30–$1,300
DIY difficulty
Moderate

Bank 2 only exists on V and boxer engines, so P0081 shows up on six- and eight-cylinder models, most often Nissan and Infiniti VQ V6 and VK V8 engines. The engine computer switches the bank 2 intake valve timing solenoid on and off many times a second and monitors the circuit; an open coil, a short or missing supply voltage sets the code. Because bank 1 keeps working, the two banks end up running different intake timing, which makes the engine feel slightly uneven rather than just flat. If the code appears on a four-cylinder, suspect a wrong code definition in the scan tool or a software problem before hunting for a second solenoid that isn't there.

Can I keep driving? Driving is fine in the short term. One bank runs with fixed intake timing, so expect a slightly rougher idle and a little less power; don't ignore it for months, because the mismatch can eventually trigger fuel trim or cam correlation codes too.

How to read P0081

How to read P0081P10203814
  1. P Powertrain
  2. 0 Generic (SAE)
  3. 0 Fuel/air & emissions (aux.)
  4. 81 Specific fault

Symptoms

  • Check engine light, often with P0021 appearing later
  • Idle a bit shaky, especially at a stop in Drive
  • Less torque when merging or towing at mid rpm
  • Bank 2 fuel trims drifting away from bank 1 on live data
  • Both P0075 and P0081 together if a shared supply has failed

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Connector or pigtail damaged, loose or oil-soaked at the bank 2 solenoid 32%
  2. Solenoid coil open or shorted 28%
  3. Harness chafed or heat-damaged along the front of the engine, often after radiator, alternator or belt work 18%
  4. Shared power feed lost (fuse or ECM relay), usually setting P0075 at the same time 12%
  5. Engine computer output for bank 2 failed 6%
  6. Scan tool or software reporting the code on an engine without a bank 2 4%

Diagnosis step by step

Diagnostic flow: P00811Check which banks are affected2Find bank 2 on your layout3Swap solenoids between banks4Measure the coil and the harness5Inspect the front harness run6Verify both banks match

  1. Check which banks are affected

    If P0075 and P0081 are both stored, don't replace two solenoids: they almost always share a power feed, so check the fuse and ECM relay output first. If only P0081 is present, the fault is somewhere between the bank 2 solenoid and the computer.

    Tools: OBD-II scanner

  2. Find bank 2 on your layout

    On transverse front-drive VQ engines (Altima, Maxima, Murano, Quest), bank 2 is the front bank facing the radiator, and its solenoid is on the timing-chain end at the passenger side. On rear-drive and truck layouts (350Z, G35/G37, Frontier, Pathfinder, Titan) bank 2 is the driver-side bank.

    Tools: Flashlight

  3. Swap solenoids between banks

    On many V engines the two intake solenoids are the same part. Unbolt them, swap sides, clear codes and run the engine. If the code moves to P0075, the solenoid is bad; if P0081 stays, the wiring or the computer on the bank 2 side is at fault.

    Tools: Screwdriver, OBD-II scanner

  4. Measure the coil and the harness

    Compare the bank 2 coil resistance with the bank 1 unit; they should read within about half an ohm of each other, typically around 7 to 8 ohms at 68 °F. Then check the harness side for 12 V supply with the key on and continuity of the control wire to the ECM.

    Tools: Multimeter

  5. Inspect the front harness run

    Look for wiring pinched under a bracket, melted near the exhaust manifold, or cut after a front-end repair. Wiggle the harness with the engine idling and a scan tool showing bank 2 cam angle; a jump or stall pinpoints the break.

    Tools: Flashlight, OBD-II scanner

  6. Verify both banks match

    After the repair, clear codes and drive with live data on screen. Target and actual intake cam angle on bank 2 should move together, and bank 2 should mirror bank 1 within a few degrees under the same load.

    Tools: OBD-II scanner

Where the parts are

Ignition: coils and spark plugs per cylinder – P00811234567
Ignition: coils and spark plugs per cylinder
  1. 1Ignition coil
  2. 2Spark plug
  3. 3Fuel injector
  4. 4Camshaft sensor
  5. 5Crankshaft sensor
  6. 6Engine computer (ECM)
  7. 7Intake manifold

Repair options & costs

RepairDIY?Estimated cost
Repair connector or pigtail at the bank 2 solenoid Yes $50–$200
Replace bank 2 intake valve timing control solenoid Yes $130–$380
Repair harness damage at the front of the engine No $120–$450
Repair shared supply (fuse, ECM relay) affecting both banks No $30–$200
Repair or replace the engine computer No $500–$1,300

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Notes by brand

Nissan

On transverse VQ35 engines the bank 2 solenoid is the easy one: it faces the radiator and can often be reached from above without removing much. The bank 1 unit sits near the firewall, which is why swapping them for a test takes more time on the rear side.

Emissions / smog test impact

Will fail

P0081 turns the check engine light on, which is an automatic fail in states with OBD emissions testing. After the repair, drive enough mixed miles for the readiness monitors to complete before retesting.

Frequently asked questions

What does bank 2 mean on my engine?

It is the cylinder bank that does not contain cylinder 1. On transverse front-drive V6 engines it is usually the front bank toward the radiator; on rear-drive cars and trucks it is usually the driver's side. Your service information confirms it for your engine.

I have P0075 and P0081 together. Are both solenoids bad?

Very unlikely. Two solenoids failing at the same time is rare; a blown fuse, bad ECM relay output or a connector shared by both circuits is the usual reason. Check the common supply before buying parts.

Can I just swap the solenoids to diagnose it?

On many V engines, yes, because both intake solenoids are the same part. If the code follows the solenoid to the other bank, replace that solenoid. If it stays on bank 2, look at wiring and the computer.

Why does the engine feel uneven instead of just weaker?

Only one bank has lost cam timing control, so the two halves of the engine breathe differently. That imbalance shows up as a slightly shaky idle and uneven fuel trims between banks.

Sources