C3748 Nissan Qx OBD Code

OBD/2 C3748 error code description and symptoms.

Vehicle Speed Sensor (VSS) Intermittent Indicates the powertrain control module (PCM) detected an error in the vehicle speed information. Vehicle speed data is received from either the vehicle speed sensor (VSS), transfer case speed sensor (TCSS), anti-lock brake system (ABS) control module, generic electronic module (GEM), or central timer module (CTM). This DTC is set the same way as C3748. However, it is intended to flash the transmission control indicator lamp (TCIL) for first time VSS circuit error/malfunctions. Refer to possible causes for C3748

One example of this would be when an automatic vehicle in placed in gear. To prevent the added drag from the torque converter and transmission from reducing the idling speed, the PCM will command the idle control valve to allow more air to enter the engine, while at the same time, adjusting the injector pulse width to inject more fuel to suit the increased amount of air. Note that the idle air control valve is closed by the PCM when the throttle plate is opened to prevent excess air from entering the engine.

C3748 Nissan Qx Error Code Repair Process :

OBD C3748 code and tailpipe testing are two different approaches to identify vehicles in need of repair. The OBD system looks for broken or malfunctioning emissions control components and abs inlet valve coil rr circuit short to battery, while tailpipe tests sample a vehicle's exhaust to see if it is above or below certain prescribed limits. Given the robust nature of today's emissions control components, it is entirely possible for an individual component to C3748 malfunction without leading to an immediate increase in emissions at the tailpipe. In such cases, other components (like the catalyst) can temporarily compensate for the part that is broken however, these other components can only do double duty for so long before they, too, begin to malfunction. In addition, OBD also monitors for C3748 and other malfunctions in the fuel system problems that traditional tailpipe tests were not designed to identify. Most state and local areas also include a gas cap pressure test as part of an emission inspection.

Common Causes of Nissan Qx C3748 OBD2 Code

A common cause of code C3748 is the failure of ABS Inlet Valve Coil RR Circuit Short To Battery, but there are several other possible causes as well, such as ;

EVAP system hose leaking
Engine Control Module (ECM)
Camshaft advance mechanism binding (VCT unit)
Oil flow restriction in the oil passages or the VCT valve body

C3748 is a kind of Chassis Trouble Code

Diagnosing chassis noises can be one of the most frustrating problems technicians face. Fortunately, manufacturers have engineered noise, vibration and harshness (NVH) diagnostic techniques and equipment to find the source of the noise.

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

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C3748 Nissan Qx OBD Code

C3748 Nissan Qx Error Code Repair Process :

Common Causes of Nissan Qx C3748 OBD2 Code

C3748 code for other Nissan cars