U0797 Mercedes-benz M Class OBD Code

OBD/2 U0797 error code description and symptoms.

HO2S Sensor Circuit Malfunction (HO2S-11) During testing the HO2S Heaters are checked for opens/shorts and excessive current draw.
The test fails when current draw exceeds a calibrated limit and/or an open or short is detected. Short to VPWR in harness or HO2S. Water in harness connector. Open VPWR circuit. Open GND circuit. Low battery voltage. Corrosion or poor mating terminals and wiring Damaged HO2S heater. Damaged PCM.

As the engine heats up and combustion becomes easier and more complete, the PCM will command the idling control valve to increase the amount of air entering the engine to suit the changing conditions. However, when the load on the engine changes, say, when some electrical consumers or other systems are either turned on or off, the PCM adapts the signal voltage to the idle control valve to ensure that the idling speed remains stable, and at the RPM specified by the manufacturer.

U0797 Mercedes-benz M Class Error Code Repair Process :

The rule of U0797 code when it comes to emissions-related vehicle repair is that any modification that changes the vehicle from a certified configuration to a non-certified configuration is considered tampering: this applies to both vehicle owners and repair facilities and is, therefore, a Federal offense. Replacing a catalyst with a straight pipe is one traditional example of injector high sides shorted together. Likewise, overriding the OBD U0797 error in system through the use of high-tech defeat devices or non-certified computer chips, for example, would also be considered tampering. The OBD system may, however, be repaired back to its original certified configuration with certified performance chips or appropriate aftermarket parts.

Common Causes of Mercedes-benz M 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 ;

Exhaust tube
Faulty front heated oxygen sensor
Camshaft Position Sensor harness is open or shorted
Incorrect fuel filler cap used

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-benz M Class OBD Code

U0797 Mercedes-benz M Class Error Code Repair Process :

Common Causes of Mercedes-benz M Class U0797 OBD2 Code

U0797 code for other Mercedes-benz cars