P3425 code meaning
Cylinder 4 Deactivation/Intake Valve Control Circuit/Open
Powertrain system Generic code P34xx codes Check engine light
What P3425 means
Cylinder 4 is one of the four cylinders that classic V8 cylinder deactivation shuts off, together with 1, 6 and 7, both at GM (Active Fuel Management) and on the Chrysler 5.7 L Hemi with MDS. That makes P3425 one of the best documented codes in this range. GM's 2019 tables for the L84 and L86 flag an open when the off-state output shows more than 200 kohm, 20 of 25 samples, Type B. Chrysler lists it as Cylinder 4 Deactivation Control Circuit; a STAR case describes the driver-side exhaust manifold heat shield wearing through the solenoid harness and asks for at least 15 mm clearance. P3427 and P3428 cover shorts on the same circuit.
P3425 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 P3425
- Check engine lamp on
- Engine stays in eight-cylinder mode
- Further circuit codes for cylinders 1, 6 and 7 if the shared harness is damaged
Common causes of P3425
- Most likelySolenoid harness chafed through by the exhaust manifold heat shield (5.7 L Hemi)
- PossibleOpen coil in the cylinder 4 deactivation solenoid
- PossibleCorroded or loose solenoid connector
- Less likelyControl module software needing an update (Chrysler TSB 18-002-25)
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 P3425 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). |
| 25 | The exact fault in that area. |
What to do next
- Note P3425 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 P3425
What does P3425 mean?
P3425 means "Cylinder 4 Deactivation/Intake Valve Control Circuit/Open". Cylinder 4 is one of the four cylinders that classic V8 cylinder deactivation shuts off, together with 1, 6 and 7, both at GM (Active Fuel Management) and on the Chrysler 5.7 L Hemi with MDS. It is a generic code, so it means the same on every make.
Is it safe to drive with P3425?
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 P3425 fail an emissions test?
Yes, it can. P3425 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 P3425 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 P3425 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.