U3864 Gmc Canyon Diagnostic Trouble Code

U3864 Gmc Canyon code definition:
U3864 is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code for Gmc Canyon.

U3864 Gmc Canyon is described as Fuel System Too Rich, which basically means bank 1's oxygen sensor has detected a rich condition of fuel. This means there's not enough oxygen in the exhaust from too much fuel being delivered into the air and gas mixture for combusion. The spark should have a light tan color. If the sensor probe comes with white and chalky parts, this means it has been lagging between switching phases, and should be replaced.

Symptoms

Symptoms of a U3864 Gmc Canyon diagnostic trouble code may include:

Vacuum leak on the engine
Reduction in engine performance, especially at low RPM levels
Engine surge
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

Possible Causes :

Fuel with a large percentage of sulfur will clog the DPF quickly
The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)

Common Misdiagnoses

IC Circuit High Voltage Problem
Control Module Throttle Actuator Position Performance Problem
Air Conditioning (A/C) Clutch Feedback Circuit High Voltage Problem
Cruise Vehicle Speed/Set Speed Difference Too High Problem
PCM Stack Overrun Problem

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble.

Process Tips

Diagnostic trouble code U3864 Gmc Canyon 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 U3864 Gmc Canyon.

Fortunately, U3864 Gmc Canyon is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.