Diagnostics Archives - Page 9 of 46 - UnderhoodService
LTF and STF Fuel Trim Engine Codes P0170, P0175, P0172, P0174

Understanding what parts should be replaced to get ride of these codes.

Starter Diagnosis: Should You Replace It, Or Not? (VIDEO)

A large amount of starters are replaced due to misdiagnosis. This video is sponsored by The Group Training Academy.

Oxygen Sensor Questions Answered

If an O2 sensor is not reading properly or is borderline, it should be replaced regardless of its age or mileage.

Audi Tech Tip: Passenger Compartment Not Warming Up?

Code B10D004 will indicate a coolant circulation pump failure.

Diagnostic Strategies For New Technicians

In my textbook, a piston or flame front would not be mentioned until the last chapter of the book.

Power Window Regulator Replacement

Blindly replacing a window regulator and motor assembly may not solve a customer’s problem.

Fixing A Steering-Pull Condition

If a customer comes to your shop with a steering-pull complaint, never jump to conclusions about what’s really wrong.

ADAS Blindspot And Cross Traffic Detection Systems

Servicing these systems is straightforward and, with the right tools, you can resolve customer complaints.

VIDEO: A Better Way To Check Wheel Bearings For Play

Old methods of checking for wheel bearing play may not be effective today. This video is sponsored by BCA Bearings by NTN.

Testing A/C Or Heater Blower Motor Circuits

The heat eventually burns out the blower motor resistor, and, in many cases, causes the electrical connector to melt.

VIDEO: Mass Air Flow Sensor Diagnostics

A mass air flow sensor measures air entering the engine. This video is sponsored by NGK Spark Plugs.

7 Reasons Direct-Injection High-Pressure Fuel Pumps Fail

High-pressure fuel pumps can malfunction and/or fail due to a number of factors.