LAUNCH X431 PAD HD: Engine State Test on 2020 Foton Aumark

August 20, 2026

LAUNCH X431 truck diagnostic tools can perform active tests on light-duty and heavy-duty trucks. For example, we can use "Engine State Monitor" to check the engine status when the accelerator pedal is pressed and released, making it easier to troubleshoot faults. In this article, we will use the LAUNCH X431 PAD V ELITE with the truck diagnostic kit to perform an "Engine State Monitor" test on a 2020 Foton Aumark.

Operating Procedure:

1) Connect the X431 PAD to the vehicle’s OBD port and operate it on the X-431 APP. Click [Diagnose] -> [Foton]. Foton diagnostic software version V15.20 or higher is recommended.

LAUNCH X431 PAD HD_Engine State Test on 2020 Foton Aumark

2) After manually selecting the vehicle model, enter the vehicle system. In this example, we first manually select the vehicle model: Click [Select Vehicle Type] -> [Conventional Energy] -> [Light Truck Series] -> [Aumark].

Then enter the vehicle system: Click [Auto Scan] -> [ECM/ABS/SCR Scan] -> [All System], and click [Click In] in the [Enter Engine System] section.

3) After confirming the vehicle information, start the vehicle. In the function menu, select [Actuation Test] -> [Engine State Monitor].

4) Press the accelefator and observe the data changes. Normally, three states can be observed:

Engine Allowed Status: Low Speed Governor State

The Engine Is Currently Idling On The Low Speed Governor. The Throttle Pedal Is Released, The Vehicle Is Stationary, And The Engine Is Idling.

Engine Allowed Status: Air Fuel Control Derate

The Engine Fueling Is Being Limited Due To Lack Of Oxygen (Boost Pressure). This State Will Normally Be Active For A Few Seconds During A Hard Acceleration To Prevent Excessive Black Smoke. Excessive Time Operating In This State Indicates The Lack Of Boost Pressure (Oxygen) Entering The Engine. Troubleshoot The Air Intake System.

Engine Allowed Status: Automotive Governor

The Automotive Throttle Is Controlling The Engine Speed. This Is A Normal State When The Throttle Pedal Is Depressed And The Automotive Governor Is Enabled.