U3959 Engine Code Repair

Meaning of U3959 engine trouble code is a kind of network trouble code and U3959 code can be about replacing a broken oxygen sensor can eventually lead to a busted catalytic convertor which can cost upwards of $2,200. Taking your car into a shop will cost you around $210 depending on the car. However, an oxygen sensor is easy to replace on many cars and is usually detailed in the owner's manual. If you know where the sensor is, you only have to unclip the old sensor and replace it with a new one. Regardless of how you approach it, you should get this fixed right away.

U3959 Fault Symptoms :

U3959 Possible Solution:

Power Steering Pressure (PSP) Switch Signal Malfunction The PCM counts the number of times vehicle speed transitions from 0 to a calibratable speed. After a calibratable number of speed transitions the PCM expects that the PSP input should have changed. This DTC is set if the transition is not detected. Vehicle towed with engine running Power steering hydraulic concern was repaired but DTC was not erased PSP switch/shorting bar damaged SIG RTN circuit open PSP circuit open or shorted to SIGRTN PCM damaged Check, if possible, if vehicle was towed or power steering service was performed. Observe PSP V PID while checking wires for intermittents.

U3959 Code Meaning :

The catalytic converter has an oxygen sensor in front and behind it. When the vehicle is warm and running in closed loop mode, the upstream oxygen sensor waveform reading should fluctuate.

Parts or components should not be replaced with reference to only a U3959 DTC. The vehicle service manual should be consulted for more information on possible causes of the fault, along with required testing.