Generic electrical fault on the temperature sensor of the exhaust camshaft position actuator on bank 1. The camshaft position sensor identifies which cylinder is on the compression stroke — without it the ECM cannot run sequential injection or coil-on-plug ignition correctly.
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.
Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank.
Symptoms
- Check engine light on
- Power loss especially in mid-rpm range
- Possible rough idle or stalling
- Increased fuel consumption
Most likely causes
- Temperature sensor failed
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: hard
- It affects emissions.
What each character of P34B4 means
- P: Powertrain: engine and transmission
- 3: Generic or manufacturer code, depending on the range
- 4: Emissions
- B4: Specific fault in that system
Frequently asked questions
Can I keep driving with code P34B4?
Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.
What causes code P34B4?
The most common causes are: temperature sensor failed.
Related codes
- P34B8B Camshaft Position Actuator Temperature Sensor Circuit Bank 2
- P34A8A Camshaft Position Actuator Temperature Sensor Circuit Bank 2
- P34A4A Camshaft Position Actuator Temperature Sensor Circuit Bank 1
Sources
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.