C3729 Diagnostic Trouble Code

C3729 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 C3729 diagnostic trouble code may include:

Reduction in engine performance, especially at low RPM levels
Vacuum leak on the engine
Diminished fuel efficiency
The engine oil will exhibit dilution from the ECUs attempts to increase engine temperature. Some vehicles advance the fuel injection timing slightly after top center to afterburn a small amount of fuel to increase exhaust temperatures. Some of this fuel enters the crankcase. When the ECU determines the necessity to regenerate the DPF, the service life of the oil be shortened significantly

Possible Causes :

A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.
Faulty IMRC actuator/sensor
Dirty air cleaner element Damaged DPF

Repair Processes :

Check to make sure they are not burnt or corroded. If in doubt, get some Electrical Contact cleaner at any parts store if cleaning of the terminals is needed. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code C3729 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 C3729.

Fortunately, C3729 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C3729 Trouble Code For Specific Cars

C3729 Holden Hd Power Door Memory Lock Relay Circuit Open
C3729 Rover 3.5-litre Ignition Coil - Cylinder 6 - Early Activation Fault
C3729 Opel Commodore Decklid Punch-Out Sensor Open Circuit
C3729 Kia Soul Secondary Switch Solenoid Circuit Malfunction
C3729 Fiat 1400 Lack Of HO2S Switch - Adaptive Fuel At Limit
C3729 Alvis Firefly Air Bag Tone Warning Indicator Circuit Short to Battery
C3729 Volkswagen Gol Ii Ride Control LR Shock Actuator Circuit Short To Battery