U3806 Porsche 937 Diagnostic Trouble Code

U3806 Porsche 937 code definition:
U3806 is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code for Porsche 937.

U3806 Porsche 937 is described as Intake Air Temperature (IAT) Circuit Malfunction. It's actually a general trouble code for a problem on IAT electrical circuit sensor, as it sends incorrect voltage input signals to the PCM. If the car doesn't start, they will proceed by testing the voltage at the fuel pump connector and see if the fuel pump relay, fuse, and PCM circuitry should be inspected.

Symptoms

Symptoms of a U3806 Porsche 937 diagnostic trouble code may include:

Diminished fuel efficiency
Fuel pressure too high
Malfunction Indicator Lamp (MIL) illuminated
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

Possible Causes :

A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.
Faulty IMRC actuator/sensor
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)

Common Misdiagnoses

TP Sensor Learn Not Complete Problem
Low Coolant Circuit Problem
Cruise Control System - Vehicle Accel Too High Problem
TFP Valve Position Switch-Drive Without Drive Ratio Problem
Problem

Repair Processes :

Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code U3806 Porsche 937 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 U3806 Porsche 937.

Fortunately, U3806 Porsche 937 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.