P3960 Diagnostic Trouble Code

P3960 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 P3960 diagnostic trouble code may include:

Fuel pressure too low
Rich or lean exhaust
Diminished fuel efficiency
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

Possible Causes :

A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Faulty IMRC actuator relay (if equipped)
Faulty IMRC actuator/sensor

Repair Processes :

Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble. 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 P3960 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 P3960.

Fortunately, P3960 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P3960 Trouble Code For Specific Cars

P3960 Kia Retona Secondary Air Injection System Incorrect Flow Detected
P3960 Chery Qq3 DPFE Sensor Hoses Reversed
P3960 Red Flag Hongki Fuel Volume Regulator Control Circuit Range/Performance
P3960 Lotus 72 Torque Converter/Brake Switch B Circuit High
P3960 Maserati Kyalami Transmission Fluid Pressure Sensor/Switch E Circuit Range/Performance
P3960 Ford M350 Mirror Driver Up/Down Motor Stalled
P3960 Ford Five Hundred Mirror Driver Down Circuit Failure