P3427 code meaning
Cylinder 4 Deactivation/Intake Valve Control Circuit Low
Powertrain system Generic code P34xx codes Check engine light
What P3427 means
P3427 is set when the cylinder 4 deactivation solenoid circuit has a path to ground. GM uses it on several 2019 V8s: the DFM engine L84, the AFM engine L86 and the LT4 of the Corvette. Once the low-side output is switched off, less than half an ohm toward ground fails the check; 20 of 25 samples, relay voltage at least 11 V, 425 rpm (L84) or 400 rpm (L86, LT4), Type B. In all three tables the criteria column names cylinder 1, an apparent copy slip. For the MDS-equipped Hemi from Chrysler, one STAR case documents an exhaust manifold shield that rubs the solenoid harness open; a bared wire touching metal there can end up as this kind of short. P3428 covers the opposite short, to battery voltage.
P3427 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P3427
- Check engine lamp after two drives
- V4 or reduced mode never engages
- Further circuit codes on other deactivating cylinders if the harness is damaged
Common causes of P3427
- Most likelyControl wire to the cylinder 4 solenoid rubbed through to ground, e.g. by a heat shield
- PossibleCylinder 4 solenoid shorted internally
- Less likelyMoisture or oil in the solenoid connector
- Less likelyDamaged driver in the engine control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cylinder deactivation solenoidWiring harnessECM
What each part of P3427 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 3 | Mixed range: generic and manufacturer-specific codes. |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 27 | The exact fault in that area. |
What to do next
- Note P3427 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P3427
What does P3427 mean?
P3427 means "Cylinder 4 Deactivation/Intake Valve Control Circuit Low". P3427 is set when the cylinder 4 deactivation solenoid circuit has a path to ground. It is a generic code, so it means the same on every make.
Is it safe to drive with P3427?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P3427 fail an emissions test?
Yes, it can. P3427 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P3427 to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P3427 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.