C1789 Diagnostic Trouble Code

C1789 is a kind of OBD-II Diagnostic C-Chassis Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a C1789 diagnostic trouble code may include:

Misfire
Misfire
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Rich or lean exhaust

Possible Causes :

The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Fuel with a large percentage of sulfur will clog the DPF quickly
An air leak forward of the DPF will change the sensor readings resulting in the code

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. Oxygen sensors signal the engine management computer the amount of oxygen present in the exhaust, which is used in determining and controlling the fuel ratio. If all testing has passed so far yet you still have the same code, check your scan tool and see if it can open and close the IMRC valve.

Process Tips

Diagnostic trouble code C1789 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 C1789.

Fortunately, C1789 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C1789 Trouble Code For Specific Cars

C1789 Allard Palm Beach Air Bag Driver Inflator Circuit Resistance Low on Squib
C1789 Tvr V8 Power Steering Pressure Sensor Circuit Range/Performance
C1789 Volkswagen Transporter
C1789 Renault 12 Gauge Driver Circuit Fault
C1789 Porsche Tapiro Fuel Rail Pressure Sensor Circuit High Input
C1789 Toyota Prius Park Brake Actuator Assembly Switch Applied Circuit Failure
C1789 Daihatsu Trevis GPS Antenna Connection Open or Short