C1921 Mercedes-benz 170 Diagnostic Trouble Code

C1921 Mercedes-benz 170 code definition:
C1921 is a kind of OBD-II Diagnostic C-Chassis Diagnostic Trouble Code for Mercedes-benz 170.

C1921 Mercedes-benz 170 or the Evaporative Emission Control System Incorrect Purge Flow is the set whenever the computer sees that there is a problem with the flow coming from the purge valve or the purge flow is not enough within the EVAP system. If the car doesn't start, they will proceed by testing the voltage at the fuel pump connector and see if the fuel pump relay, fuse, and PCM circuitry should be inspected.

Symptoms

Symptoms of a C1921 Mercedes-benz 170 diagnostic trouble code may include:

Reduction in engine performance, especially at low RPM levels
Vacuum leak on the engine
Diminished fuel efficiency
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Dirty air cleaner element Damaged DPF

Common Misdiagnoses

TP Sensor Learn Not Complete Problem
Low Coolant Circuit Problem
Cruise Control System - Vehicle Accel Too High Problem
TFP Valve Position Switch-Drive Without Drive Ratio Problem
Problem

Repair Processes :

Find out what kind of system you have and verify that voltage to the fuel level sensor is present at the fuel pump wiring harness. You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data.

Process Tips

Diagnostic trouble code C1921 Mercedes-benz 170 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before C1921 Mercedes-benz 170.

Fortunately, C1921 Mercedes-benz 170 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.