U0477 Trouble Code

View U0477 obd/2 error code description and symptoms. U0477 engine photo

Catalytic converters must be warm before they can work properly. On a cold start the PCM provides a rich mixture to keep the cold engine running.
All that extra fuel goes into the catalytic converter. But the exhaust isn't very hot, because, ah, the engine is pretty cold. GM has employed several strategies to fire up the catalytic converter quicker and reduce cold start emissions. One way is to use a secondary air pump that pumps outside air directly into the catalytic converter.

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)
Level
Repair Time (35 Min.)
Time
Cost Prediction : $ 50-100

U0477 Error Code Repair Process :

OBD U0477 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 fuel level sensor circuit high input, 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 U0477 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 U0477 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.

Wrench Tool U0477 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 U0477

A common cause of code U0477 is the failure of Fuel Level Sensor Circuit High Input, but there are several other possible causes as well, such as ;

U0477 code for all cars

You can view according U0477 DTC for your car model. We selected several models to see obd2 solutions click and view it.

+U0477 Subaru Impreza 3 +U0477 Jaguar 240 +U0477 Nissan Sedan +U0477 Opel Zafira B +U0477 Tornado Typhoon

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

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