C0971 Diagnostic Trouble Code

C0971 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 C0971 diagnostic trouble code may include:

Engine surge
Blown fuse (if applicable)
Lack of power
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)
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)

Repair Processes :

Now, clear the codes and test-drive the vehicle to see if the code is reset. 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 C0971 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 C0971.

Fortunately, C0971 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0971 Trouble Code For Specific Cars

C0971 Hyundai Veracruz SCP (J1850) Invalid or Missing Data for Engine RPM
C0971 Emf 30 Injection Pump Fuel Metering Control "A" Range/Performance (Cam/Rotor/Injector)
C0971 Mercedes Cls 400 ABS Outlet Valve Coil RF Circuit Short To Ground
C0971 Mbm Coupe Tourism A/C Post Heater Sensor Circuit Short To Ground
C0971 Standard Vanguard Lamp Keypad Output Short Circuit To Battery
C0971 Fiat V8 Left Lamp Outage Signal Circuit Short to Ground
C0971 Toyota Gt1 Oil Change Reset Button Circuit Open