P340A code meaning
Deactivation/Intake Valve Control Circuit Bank 1
Powertrain system Generic code P34xx codes Check engine light
What P340A means
P340A is meant for engines that switch the intake valves of a whole bank through a shared control circuit, rather than one solenoid per cylinder. It reports an electrical fault in that bank 1 circuit, without saying whether it is open or shorted. No manufacturer documents this code publicly, which leaves it without known limits; CARB merely demands that outputs of this kind be monitored for breaks and shorts. The common systems are built per cylinder: GM's DFM V8 has one solenoid per cylinder in the valley, so faults go to codes such as P3401. Honda's VCM V6 reports bank-level trouble as P3400. Bank 2 is P340B, the exhaust side P340C, the bank 1 function check P341A. Expect a warning lamp and no reduced-cylinder mode.
P340A 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 P340A
- Check engine lamp on
- Cylinder deactivation disabled on bank 1
- Higher fuel consumption at light load
Common causes of P340A
- PossibleDamaged, open or shorted wire in the bank 1 control circuit
- PossibleCorroded or loose connector at the bank 1 actuator
- PossibleBank 1 intake deactivation actuator with open or shorted coil
- Less likelyOutput stage fault 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 P340A 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). |
| 0A | The exact fault in that area. |
What to do next
- Note P340A 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 P340A
What does P340A mean?
P340A means "Deactivation/Intake Valve Control Circuit Bank 1". P340A is meant for engines that switch the intake valves of a whole bank through a shared control circuit, rather than one solenoid per cylinder. It is a generic code, so it means the same on every make.
Is it safe to drive with P340A?
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 P340A fail an emissions test?
Yes, it can. P340A 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 P340A 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 P340A clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.