2023 Edition Archives - UnderhoodService
Diesel Particulate Filter Regeneration

The DPF has thousands of tiny channels that trap the soot and prevent the particulate matter from exiting out the tailpipe.

Diagnosing Intercooler Boost Trouble Code P0299

The criteria for setting the code is very basic.

Understanding Engine Misfire Codes

When the fuel/air mixture ignites, many factors must be met to pass a misfire monitor.

Belt Service For Hybrid and Stop/Start Systems

Knowing how to “force start” a hybrid vehicle can be helpful if you are trying to diagnose a noise problem.

Ignition Coil Output

To see inductance inside the primary windings, use an amp probe placed around the positive wire for the ignition coil.

Monitor Water Quality When Servicing Coolant

The harder the water, the more likely the water pump is to develop a leak.

Diagnosing Misfires

What if there are no codes and a misfire is intermittent? This is where it gets complicated.

Repairing Wiring Harnesses

A guide to probing and poking.

Lifter Deactivation

The area of contact between the lifters and cam lobes is the highest loaded surface inside an engine.

Diagnostic Procedures For Stop/Start Systems

Stop/start technology is more than just a switch wired to the brake pedal and starter.

Diesel Air Filter Replacement

Here are some diesel air filter replacement tips in order to keep these vehicles running as intended.

Auxiliary Cooling Pumps

An auxiliary cooling pump’s primary function is to circulate warm coolant to the heater core.