U3934 Trouble Code

View U3934 obd/2 error code description and symptoms. U3934 engine photo

The Transmission Range Sensor (also referred to as the PRNDL input an/or neutral safety switch) tells the transmission control module (TCM) an the engine control module (PCM) that the transmission is in park, reverse, neutral, drive, low, 2nd, 3rd etc. It is attached directly to the manual valve of transmission, so when the shift lever is moved from park to drive, the Transmission Range Sensor communicates this critical information to the above mentioned vehicle control module systems.

As long as the throttle plate remains closed, the idling speed and quality is controlled by the PCM via the idle control valve, and as can be seen from the above it should be clear that idle control on a gasoline engine is a complex affair. For instance, if the engine is started in sub-zero temperatures, the PCM will command the idling control valve to allow less air to enter the engine to enrich the air/fuel mixture to create a condition which is roughly analogous to how chokes worked on carburetted engines to control idling in cold weather.

U3934 Error Code Repair Process :

If your vehicle failed a U3934 test and the U3934 Check Engine Light is NOT on, chances are you have a problem with the OBDII system, a burned out MIL lamp, or a faulty catalytic converter. The converter is essentially an afterburner that cleans up the exhaust after it exits the engine. The OBDII system uses trans temp sensor circuit open or shorted to pwr or gnd a ownstream oxygen sensor to monitor the efficiency of the converter, and it should detect a drop in converter efficiency if the converter has been contaminated or is failing (ignition misfiring, leaky exhaust valves, and oil burning can all damage the converter). What you want to look trans temp sensor circuit open or shorted to pwr or gnd: Any conditions that might cause ignition misfire, an overly rich or lean fuel condition, or loss of compression. Use your OBD Express DIY to look at the oxygen sensor outputs, coolant temperature, airflow, calculated engine load, and inlet air temperature.

U3934 is a kind of Network Trouble Code

U-code indicates that engine communication errors and shows lost communication with engine parts.U-Codes are fairly straight forward, given all of the articles and technical publications that have been written regarding these problematic codes. In most cases, it just comes down to identifying the module that isn't communicating with the other modules on the CAN bus line for whatever reason.

Common Causes of U3934

A common cause of code U3934 is the failure of Trans Temp Sensor Circuit Open or Shorted to Pwr or Gnd, but there are several other possible causes as well, such as ;

Air fuel ratio (A/F) Sensor 1 Bank 1 harness is open or shorted
Erratic camshaft position due to low oil pressure
Intake Valve Timing Control Solenoid Valve circuit poor electrical connection
Clogged or faulty fuel injector (s)

U3934 code for all cars

You can view according U3934 DTC for your car model. We selected several models to see obd2 solutions click and view it.

Engine OBD 2 Codes website is a freeware resource center for engine trouble codes.

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