The issue covered by the bulletin involves a power steering noise/whine or fluid leak from the power steering pump, gear or high pressure side power steering hose during extreme low outdoor temperature operation.
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.
OBD U2156 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 rf side repeater lamp output ckt 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 U2156 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 U2156 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.
Difficulty Level (Expert)
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Repair Time (35 Min.)
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| Cost Prediction : $ 50-100 |
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U2156 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. |
You can view according U2156 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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