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 P0749. However, it is intended to flash the transmission control indicator lamp (TCIL) for first time VSS circuit error/malfunctions. Refer to possible causes for P0749
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.
Difficulty Level (Expert)
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Repair Time (35 Min.)
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| Cost Prediction : $ 50-100 |
OBD P0749 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 p0749 pressure control solenoid a intermittent, 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 P0749 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 P0749 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.
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P0749 is a kind of Powertrain Trouble Code
Powertrain of a modern automobile, comprising engine (with exhaust system), transmission, drive shaft, suspension and the wheels. In a motor vehicle, the term powertrain or powerplant describes the main components that generate power and deliver it to the road surface, water, or air. |
You can view according P0749 DTC for your car model. We selected several models to see obd2 solutions click and view it.
| +P0749 Ultima Spyder | +P0749 Dkw F91 | +P0749 Dodge Lancer | +P0749 Facel Vega Facellia | +P0749 Unipower 1275 |
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