A failed temperature sensor integrated into the camshaft position actuator, reading lower than actual temperature.; A short to ground in the sensor signal wire between the actuator and the powertrain control module.; Corroded, loose, or damaged electrical connector pins at the actuator or the module.; An open or high-resistance ground circuit shared by the sensor, causing a false low signal.; Internal fault in the powertrain control module's sensor input circuit, though this is less common.; Aftermarket or remanufactured actuator installed with a sensor that does not meet the original calibration.

DTC codes / P34xx · Auxiliary emission controls / P34B6

P34B6B Camshaft Position Actuator Temperature Sensor Circuit Low Bank 1

P34B6 is a generic OBD-II code indicating that the powertrain control module has detected a low signal voltage from the temperature sensor integrated into the bank 1 B camshaft position actuator circuit. The computer expects the sensor to report a voltage within a calibrated range, and a sustained low reading tells it the sensor circuit is likely shorted to ground or otherwise compromised.

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 uneven engine operation if the actuator temperature affects camshaft phasing strategy.
Reduced engine performance or power delivery under certain operating conditions.
Intermittent stalling or hesitation when the engine is cold or during the first few minutes of operation.
A stored freeze-frame showing low sensor voltage, which may not correspond to any driver-perceived issue.

Common causes, most likely first

A failed temperature sensor integrated into the camshaft position actuator, reading lower than actual temperature.
A short to ground in the sensor signal wire between the actuator and the powertrain control module.
Corroded, loose, or damaged electrical connector pins at the actuator or the module.
An open or high-resistance ground circuit shared by the sensor, causing a false low signal.
Internal fault in the powertrain control module's sensor input circuit, though this is less common.
Aftermarket or remanufactured actuator installed with a sensor that does not meet the original calibration.

How to diagnose and fix it

Connect a scan tool and verify P34B6 is current or pending, then record freeze-frame data to see the sensor voltage at the time of fault.
Visually inspect the actuator connector and wiring harness for chafing, corrosion, or loose pins, and repair any obvious damage.
Back-probe the sensor signal wire at the actuator and measure voltage with the key on, engine off, comparing it to the manufacturer's expected range.
Disconnect the actuator and check for a short to ground on the signal wire using a multimeter set to resistance or continuity.
If the wiring and connectors test good, substitute a known-good actuator of the same part number and clear the code to see if it returns.
Check the sensor ground circuit for excessive resistance by measuring voltage drop between the actuator ground pin and battery negative.
After any repair, clear codes and perform a road test with the scan tool monitoring the sensor voltage to confirm the fix.

When the sensor is not the culprit

A low voltage reading from this sensor often results from a shorted signal wire where the harness rubs against a metal bracket near the front of the engine, not from a failed actuator.
Technicians sometimes replace the entire camshaft actuator assembly when only the small temperature sensor, which may be serviced separately on some engines, has failed.
The code can set intermittently due to water intrusion into the connector after a car wash or heavy rain, leaving no permanent fault when tested in a dry shop.
A weak or failing battery can cause the module to log a low sensor voltage during cranking, so always check battery condition before condemning the sensor.
This circuit shares a ground with other engine sensors on many vehicles, so a bad ground can set P34B6 along with unrelated sensor codes.

Can I keep driving with P34B6?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy acceleration and sustained high-speed driving because the fault may affect camshaft phasing and emissions. If the check engine light begins flashing or the engine runs poorly, stop driving and have the vehicle towed.

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.