Faulty camshaft position actuator temperature sensor.; Damaged or corroded wiring or connector at the sensor or actuator.; Open circuit or high resistance in the sensor signal circuit.; Short to voltage in the sensor reference or signal circuit.; Failed camshaft position actuator (oil control valve) affecting sensor readings.; Contaminated engine oil or sludge blocking the actuator oil passages, causing overheating.; Rarely, a faulty powertrain control module.

DTC codes / P34xx · Auxiliary emission controls / P34B7

P34B7B Camshaft Position Actuator Temperature Sensor Circuit High Bank 1

P34B7 indicates that the powertrain control module has detected an abnormally high voltage signal from the camshaft position actuator temperature sensor on bank 1. The sensor circuit is reporting a temperature that is higher than the plausible range, which the computer interprets as a fault in the sensor, its wiring, or the actuator itself.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms.
Rough idle or engine misfire, particularly when the engine is cold or under light load.
Reduced engine performance or power, as the variable cam timing may be limited.
Poor fuel economy due to incorrect camshaft phasing.
In rare cases, the engine may enter limp mode or stall.
Intermittent symptoms if the fault is due to a loose connection or chafed wire.

Common causes, most likely first

Faulty camshaft position actuator temperature sensor.
Damaged or corroded wiring or connector at the sensor or actuator.
Open circuit or high resistance in the sensor signal circuit.
Short to voltage in the sensor reference or signal circuit.
Failed camshaft position actuator (oil control valve) affecting sensor readings.
Contaminated engine oil or sludge blocking the actuator oil passages, causing overheating.
Rarely, a faulty powertrain control module.

How to diagnose and fix it

Perform a visual inspection of the sensor, actuator, and wiring for damage, corrosion, or oil leaks.
Check for technical service bulletins or recalls related to the camshaft actuator temperature sensor circuit.
Measure the sensor resistance and compare to specifications; replace if out of range.
Backprobe the sensor connector to check reference voltage (typically 5V) and ground integrity.
Inspect the camshaft actuator for sludge or mechanical binding; clean or replace as needed.
Verify engine oil condition and change oil and filter if contaminated.
Clear the diagnostic trouble code and perform a road test to confirm the repair.

Common oversights when diagnosing P34B7

A high voltage reading often results from a short to voltage in the signal circuit, which can be caused by a chafed wire rubbing against a hot exhaust component.
The camshaft position actuator temperature sensor is sometimes integrated into the actuator assembly, so replacing just the sensor may not be possible or cost-effective.
Engine oil sludge or lack of maintenance can cause the actuator to overheat and trigger this code, so always check oil condition before replacing parts.
This code can be set by a poor ground connection at the actuator, which is often overlooked during diagnosis.
In some vehicles, the sensor circuit shares a reference voltage with other sensors; a fault in one can affect the other, leading to misdiagnosis.

Can I keep driving with P34B7?

Driving with P34B7 is generally safe for short distances, but avoid heavy acceleration or towing until the fault is repaired. Prolonged driving may lead to reduced fuel economy or engine performance, and in rare cases, limp mode.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.