U0797 Mercedes Gle Class OBD Code

OBD/2 U0797 error code description and symptoms.

EGR Flow Insufficient Detected The EGR system is monitored during steady state driving conditions while the EGR is commanded on.
The test fails when the signal from the DPF EGR sensor indicates that EGR flow is less than the desired minimum. Vacuum supply EGR valve stuck closed EGR valve leaks vacuum EGR flow path restricted EGRVR circuit shorted to PWR VREF open to D.P.F. EGR sensor D.P.F. EGR sensor downstream hose off or plugged EGRVR circuit open to PCM VPWR open to EGRVR solenoid D.P.F. EGR sensor hoses both off D.P.F. EGR sensor hoses reversed Damaged EGR orifice tube Damaged EGRVR solenoid Damaged PCM Perform KOER self-test and look for DTC U0797 as an indication of a hard fault.

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.

U0797 Mercedes Gle Class Error Code Repair Process :

OBD U0797 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 injector high sides shorted together, 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 U0797 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 U0797 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 Mercedes Gle Class U0797 OBD2 Code

A common cause of code U0797 is the failure of Injector High Sides Shorted Together, but there are several other possible causes as well, such as ;

Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
Engine Control Module (ECM)
Ignition coils harness is open or shorted
Open or short in the VCT circuit

U0797 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.

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

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U0797 Mercedes Gle Class OBD Code

U0797 Mercedes Gle Class Error Code Repair Process :

Common Causes of Mercedes Gle Class U0797 OBD2 Code

U0797 code for other Mercedes cars