Powertrain, shared range

P34B4 B Camshaft Position Actuator Temperature Sensor Circuit Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P34B4 reports that the circuit of the temperature sensor on camshaft actuator B, bank 1, cannot be evaluated: an open line, a disconnected plug or a reading that fits no valid state. In the supplier list of NTN-SNR the letter B stands for the outlet camshaft, so the code targets an exhaust phaser turned by an electric motor whose electronics need heat protection. An Aisin patent mounts such a sensor on the motor control board and calls the intake shaft merely an example. We found no carmaker that publishes P34B4; the 2022 Mitsubishi Outlander, for instance, drives only its intake cam electrically and shifts the exhaust cam with an oil control solenoid. Expect restricted exhaust phasing until the circuit is repaired. Low and high faults: P34B6, P34B7.

Likely causes

Plug at the exhaust actuator not seated or wire broken
Temperature sensor in the actuator electronics failed
Faulty input stage in the controlling module

Symptoms

  • Malfunction indicator lamp lit
  • Exhaust cam timing on bank 1 fixed or limited
  • Driving usually unaffected

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–800
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

cam actuator b temp sensor b1sensor wiring

Related codes

P34B5P34B6P34B7P34B8P34A4P34C8

References: law.cornell.edu, ntn-snr.com, patents.google.com, mitsubishitechinfo.com.