B3688 Diagnostic Trouble Code

B3688 is a kind of OBD-II Diagnostic B-Body 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 B3688 diagnostic trouble code may include:

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
Faulty or damaged wiring
Hesitation upon acceleration
Engine surge

Possible Causes :

Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)
Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.
Defective ECU strategies or components will prevent proper regeneration

Repair Processes :

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. 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 at the plug wires to make sure they are not burnt or laying on the exhaust.

Process Tips

Diagnostic trouble code B3688 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 B3688.

Fortunately, B3688 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B3688 Trouble Code For Specific Cars

B3688 Acura Rl ABS Inlet Valve Coil LF Circuit Short To Ground
B3688 Fiat 8v LAMP DOME OUTPUT Circuit Failure
B3688 Plymouth Cambridge Evaporative Emission Control System Pressure Sensor High Input
B3688 Honda Saber Reference Voltage Out of Range (+5 v)
B3688 Gaz Chaika O2 Sensor Circuit Slow Response (Bank 2 Sensor 1)
B3688 Hyundai Eon
B3688 Volvo V4