P34B8 code meaning
B Camshaft Position Actuator Temperature Sensor Circuit Bank 2
Powertrain system Generic code P34xx codes Check engine light
What P34B8 means
P34B8 is the circuit fault for the heat sensor inside exhaust camshaft actuator B of bank 2, the row without cylinder 1 on a V or flat engine. If P34B4 is stored at the same time, a shared feed, a common ground or the control module is more likely than two failed sensors at once. The code family presumes an electrically driven exhaust phaser with its own heat-sensitive driver: NTN-SNR files it under outlet camshaft adjustment, and Aisin's patent explains why such a driver carries a temperature sensor at all. A carmaker using P34B8 could not be found in bulletins or official service information. In practice: check plug and harness on bank 2 first, then the actuator itself. For a signal stuck low or high on bank 2 see P34BA and P34BB.
P34B8 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 3.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P34B8
- Malfunction indicator lamp lit
- Exhaust phasing on bank 2 restricted, banks may run slightly unevenly
Common causes of P34B8
- Most likelyConnector or harness at the bank 2 exhaust actuator open
- PossibleShared supply or ground faulty (when bank 1 also reports)
- PossibleTemperature sensor in the bank 2 actuator failed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cam actuator b temp sensor b2Sensor wiring
What each part of P34B8 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). |
| B8 | The exact fault in that area. |
What to do next
- Note P34B8 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 P34B8
What does P34B8 mean?
P34B8 means "B Camshaft Position Actuator Temperature Sensor Circuit Bank 2". P34B8 is the circuit fault for the heat sensor inside exhaust camshaft actuator B of bank 2, the row without cylinder 1 on a V or flat engine. It is a generic code, so it means the same on every make.
Is it safe to drive with P34B8?
Drive gently and only to a workshop. With P34B8 the car can go into limp mode (reduced power) to protect itself.
Will P34B8 fail an emissions test?
Yes, it can. P34B8 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 P34B8 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P34B8 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.