C0086 Diagnostic Trouble Code

C0086 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 C0086 diagnostic trouble code may include:

Engine surge
Blown fuse (if applicable)
Lack of power
Rich or lean exhaust

Possible Causes :

Faulty IMRC actuator relay (if equipped)
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)

Repair Processes :

If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector.

Process Tips

Diagnostic trouble code C0086 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 C0086.

Fortunately, C0086 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0086 Trouble Code For Specific Cars

C0086 Fiat Punto Lamp Warning Relay Circuit Failure
C0086 Renault Vel Satis HO2S Heater Control Circuit Low (Bank 2 Sensor 2)
C0086 Jeep Cj2 Seat Driver Rear Down Switch Circuit Short To Battery
C0086 Datsun 2300 High Mount Stop Lamp Circuit Failure
C0086 Bmw 528 Chime Input Request Circuit Short To Ground
C0086 Vauxhall Maxx Pressure Control Solenoid B Control Circuit / Open
C0086 Porsche 962 Fuel Level Sensor B Intermittent/Bypass Line Monitor