P1071 Diagnostic Trouble Code

P1071 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 P1071 diagnostic trouble code may include:

Faulty or damaged wiring
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
Poor fuel economy
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.
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.

Repair Processes :

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. 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.

Process Tips

Diagnostic trouble code P1071 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 P1071.

Fortunately, P1071 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P1071 Trouble Code For Specific Cars

P1071 Nissan Sunny Cruise Control/Brake Switch A Circuit Malfunction
P1071 Rover P4 Ignition Coil Secondary Circuit Failure
P1071 Smart Ultimate Lamp Anti-Theft Indicator Circuit Short To Ground
P1071 Citroen Xanae Fuel Rail Pressure Sensor Circuit Intermittent
P1071 Porsche 959 Fuel Level Sensor B Circuit Malfunction
P1071 Chrysler Grand Voyager Evaporative Emission Control System Incorrect Purge flow
P1071 Geely Uliou Oil Change Lamp Circuit Open