P1809 Diagnostic Trouble Code

P1809 is a kind of OBD-II Diagnostic P-Powertrain 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 P1809 diagnostic trouble code may include:

The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Faulty PCM
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Diminished fuel efficiency

Possible Causes :

An air leak forward of the DPF will change the sensor readings resulting in the code
Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
Fuel with a large percentage of sulfur will clog the DPF quickly

Repair Processes :

If you find a related TSB, the information will often help in diagnosing the code in question as TSBs are crested from many thousands of repairs. With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground.

Process Tips

Diagnostic trouble code P1809 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 P1809.

Fortunately, P1809 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P1809 Trouble Code For Specific Cars

P1809 Kia Magentis Seatbelt Driver Pretensioner Circuit Failure
P1809 Mercedes B 170 ABS Hydraulic Pressure Differential Switch Input Short Circuit To Battery
P1809 Zaz Jalta SCP (J1850) Invalid or Missing Data for Vehicle Speed Control
P1809 Panhard L6 Driver Power Window One Touch Window Relay Circuit Short To Ground
P1809 Dkw Special Ignition Coil - Cylinder 3 - Early Activation Fault
P1809 Brewster Brewster Coolant Temp Out of Range
P1809 Hispano Suiza H6 Pedal Correlation PDS2 and LPDS High