September 2019 Archives - UnderhoodService
What Causes Direct Fuel Injectors To Clog?

In the case of a direct fuel injector where the tip is exposed to the combustion event, carbon can stick to the nozzle and cause a bad spray pattern, because carbon searches for other carbon.

Dodge Tech Tip: MIL Lamp From Oxygen Sensor

If the 2010-2014 Dodge Ram 2500 or 3500 has any O2 sensor-related DTCs stored, pending or active, perform the repair procedure. Both oxygen sensor connectors should be removed and new connectors with pigtails installed. The pigtail splice points should be staggered to eliminate bulk in the harness.

Honda Tech Tip: Low Tire Pressure And TPMS Indicator On After Recent Tire Replacement

The Honda CR-V uses an indirect TPMS system that uses the rolling circumference of the tire to determine the pressure in the tire. Differences in sidewall construction and weight of a replacement tire can cause the rolling circumference to change if a single tire is replaced.

GM Tech Tip: Power Steering Fluid Leak At Reservoir Or Reservoir Connection

When diagnosing power steering fluid leak conditions, the technician may find a heat-damaged fluid reservoir. When a power steering reservoir or reservoir seal is damaged, it’s important to make sure that potential associated issues are addressed.

Ford Tech Tip: Lamp Flashing And Multiple Diagnostic Trouble Codes Present

Some customers may complain of intermittent nuisance activation of the electronic stability control (ESC) during low-speed turning maneuvers while towing only a trailer.

Mini Cooper Tech Tip: False “Service Due” Message For Brake Pad Thickness

Brake pad thickness warning message is displayed even if the pads are above specifications.

SAAB Tech Tip: Low Oil Pressure And Code P0521

Some customers may complain of low oil pressure, no oil pressure, and/or engine noise as well as a possible P0521, which may be the result of a sticking oil pump pressure relief valve. In some instances, this may occur intermittently if the valve frees up when the engine cools down.

TPMS Radio Frequency Theory And Operation

A typical wheel-mounted TPMS sensor will transmit data about tire pressure and temperature. Newer, tire-mounted models can also gauge acceleration and, in some cases, the direction that the wheel is spinning. Some systems display tire pressure by location on the instrument panel, but most do not.

10 Cartridge Oil Filter Tips

An oil change is probably one of the least expensive services your shop offers, but it can result in one of the most costly comebacks if a mistake is made.

Better Engines Need Better Filters

Neglected oil change intervals can ruin the best engine oils and filters. As engine oil and the filter accumulate miles, they become contaminated with carbon, water and various acids, all of which are a byproduct of internal combustion that combine to form a film of black, gooey sludge on the interior parts of the engine.

Programming Keys, Codes And Diagnostics

In the 1980s, the only thing standing between a thief and starting a car was the lock’s tumbler. The thief could pick the lock or violently remove the lock’s tumbler with a slide hammer. Re-keying a car involved installing a new lock cylinder – this is not the case with most late-model vehicles.

Understanding Idle Quality

Idle quality is challenging to diagnose because it is a vague description at best on most vehicles. The textbook definition is an engine speed lower or higher than the specification in the service manual. For drivers, idle “quality” is more difficult to define.