P3489 reports that the circuit to the actuator for deactivation or the intake valve of cylinder 12, the highest cylinder number in this code series, is open. No manufacturer documents this code publicly; J2012 reserves the codes for cylinders 9 to 12 for engines with more than eight cylinders. Twelve-cylinder engines with shut-off span Mercedes' late-1990s V12, which deactivated every second cylinder in the firing order, Lamborghini's Aventador V12 that shuts down one cylinder bank below 135 km/h, and Bentley's W12. The Mercedes engine used a hydraulic solenoid pack, the kind of part such a circuit would drive; the bank-based systems publish no equivalent. Comparable logic on GM V8s calls a circuit open above 200 kohm with the output idle. P3491 and P3492 report shorts, P3490 a functional fault, P3493 the exhaust valve.
Medium severity. Can I keep driving?Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.
Cylinder 12 is numbered according to the manufacturer: check your engine's manual before working on it.
Symptoms
- Check engine lamp on
- Engine no longer runs in reduced-cylinder mode
- Somewhat higher fuel use on the highway
Most likely causes
- Wire to the cylinder 12 actuator open or chafed
- Cylinder 12 actuator coil open
- Loose or corroded connector at cylinder 12
- Output stage of the control module failed
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P3489 means
- P: Powertrain: engine and transmission
- 3: Generic or manufacturer code, depending on the range
- 4: Emissions
- 89: Specific fault in that system
Frequently asked questions
Can I keep driving with code P3489?
Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.
What causes code P3489?
The most common causes are: wire to the cylinder 12 actuator open or chafed; cylinder 12 actuator coil open; loose or corroded connector at cylinder 12.
Related codes
- P3490Cylinder 12 Deactivation/Intake Valve Control Performance
- P3491Cylinder 12 Deactivation/Intake Valve Control Circuit Low
- P3492Cylinder 12 Deactivation/Intake Valve Control Circuit High
- P3493Cylinder 12 Exhaust Valve Control Circuit/Open
- P3400Cylinder Deactivation System Bank 1
- P3497Cylinder Deactivation System Bank 2
- P0312Cylinder 12 Misfire Detected
Sources
- law.cornell.edu: 13 CCR 1968.2
- en.wikipedia.org: Variable displacement
- newatlas.com: 24363
- gsi.ext.gm.com: 19OBDG03B Diagnostics
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.