What Types of Errors Can a Diagnostic Tool Find?

With the potential to detect specific issues before they spiral into full-blown malfunctions, diagnostic tools are transforming how to approach maintenance and repair within the heavy equipment industry. Understanding the errors that heavy duty equipment diagnostics uncover helps to maintain efficiency and safety. Here are the types of errors that a diagnostic tool specialized in heavy-duty equipment will help find and what these errors mean for the health and performance of your assets:

Check Engine Light

The check engine light is your truck’s way of telling you something is amiss. This light can signal and convey a myriad of issues within the engine. Understanding the error codes is the first step in deciphering the warning. Here are some standard error codes and what they indicate:

P0171 and P0174 

When codes P0171 and P0174 illuminate your dashboard, your truck’s engine air-fuel mixture is leaning out in an imbalanced way. This could signify a vacuum leak, a weak fuel pump, or a clogged fuel filter. Left unchecked, it leads to poor engine performance, decreased fuel efficiency, and engine damage over time.


This error message spells trouble for your ignition system, manifesting in rough idling, power loss, and higher emission levels. Causes range from faulty spark plugs or ignition coils to serious issues like a failing head gasket. Ongoing misfires lead to increased fuel consumption and higher emissions. They can also cause severe damage to the engine’s internal components over time. 


Error code P0420 is often associated with problems in your truck’s catalytic converter. It can also be caused by a failed oxygen sensor, engine misfire, or even a problem with the exhaust system. Neglecting this error may lead to a failing emission control system and a harmful environmental impact.

ABS and Airbag Faults

Beyond the engine’s functionality, the anti-lock braking system (ABS) and airbag systems are integral to driver and passenger safety. Heavy duty equipment diagnostics can help identify potential issues before they become critical. Common errors in these systems include:


A C0040 error points to a malfunction of the right front wheel speed sensor circuit, which can compromise the accuracy of the ABS. This can affect the vehicle’s ability to stop safely on slippery surfaces. This error often stems from a broken wire or a defective sensor.


An airbag deployment error is a severe safety concern, especially if it occurs without a crash event. A B0028 error could be due to a short circuit in the front right airbag module, faulty wiring, or problems in the airbag deployment mechanism. It requires immediate attention for your truck’s safety systems to be operational.

Transmission Errors

Modern vehicles, including heavy-duty trucks, have highly sophisticated transmission systems that directly affect the vehicle’s performance and drivability. Diagnostic tools help in identifying issues early on, such as:


This error is a warning that the transmission control system is compromised. It’s a preliminary step in detecting underlying transmission issues such as solenoid malfunctions and faulty sensors. It also indicates a failing transmission control module.


A P0730 code indicates that the transmission has detected an issue within the gear ratio parameters. This could be due to a slipping transmission, clutch problems, or an internal transmission mechanical failure. If left unresolved, this issue can cause extensive damage to the transmission system.

Buy Heavy Duty Equipment Diagnostics Today

With the high stakes associated with heavy-duty equipment maintenance, errors are potential disasters waiting to happen. By understanding and leveraging the diagnostic capabilities of modern tools, you can stay one step ahead of catastrophic failures and regulatory pitfalls. Upgrade your diagnostic toolkit today to optimize heavy-duty equipment performance and reliability.

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