P0746 Diagnostic Trouble Code

P0746 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 P0746 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.
Reduction in engine performance, especially at low RPM levels

Possible Causes :

Dirty air cleaner element Damaged DPF
A plugged converter will cause of host of driveability problems as well as set this code. A severely plugged converter will result in the inability to increase rpm when under load. Look for a code such as P0421 -- catalytic converter efficiency below threshold if the converter indicating a faulty converter.
An air leak forward of the DPF will change the sensor readings resulting in the code

Repair Processes :

If the engine displays a miss and there wasn't a code, determine which cylinder is misfiring. If the exhaust manifold is visible, spay or pour a small amount of water on each cylinder exhaust port. Water will evaporate immediately on good cylinders and slowly on the missing cylinder. If this can't be accomplished pull the plugs and check the condition. Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble. 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.

Process Tips

Diagnostic trouble code P0746 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 P0746.

Fortunately, P0746 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P0746 Trouble Code For Specific Cars

P0746 Mercedes C 250 ABS Inlet Valve Coil LF Circuit Short To Battery
P0746 Dodge 1500 Ignition Coil A Secondary Circuit Malfunction
P0746 Citroen C1 Ii Front Sounder Circuit Short to Vbatt
P0746 Toyota Premio Park / Neutral Switch Input Circuit High
P0746 Lotus 33 Torque Converter Clutch Solenoid Failed On
P0746 Mercedes-benz 190 Air Bag Memory Clear Circuit Open
P0746 Mg C-type Air Suspension RR Air Spring/Shock Solenoid Output Circuit Open