C3701 Diagnostic Trouble Code

C3701 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 C3701 diagnostic trouble code may include:

Possible spark knock (detonation / pre-ignition)
Poor fuel economy
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
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.
Defective ECU strategies or components will prevent proper regeneration

Repair Processes :

Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed. You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code C3701 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 C3701.

Fortunately, C3701 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C3701 Trouble Code For Specific Cars

C3701 Alpine A310 Air Bag passenger Circuit Open - Loop #2
C3701 Iveco Vertis Seat Direction Switch Assembly Circuit Short To Battery
C3701 Toyota Crown O2 Sensor Circuit Slow Response (Bank 1 Sensor 3)
C3701 Stanley 20 Lamp Keypad Output Short Circuit To Ground
C3701 Mitsubishi Space Runner Aux Heater Overheat Sensor Circuit Short to Ground
C3701 Talbot Saoutchik Mirror Passenger Left Circuit Short To Battery
C3701 Talbot Sunbeam Mirror Passenger Right Circuit Failure