July 2019 Archives - UnderhoodService
Auxiliary Water Pump Diagnostics

A car or truck comes into your shop with a complaint of poor heater performance- the issue may be the auxiliary water pump.

GM Tech Tip: Service ABS / TCS / Power Steering, Suspension Message

Monitor the voltage on the communication enable circuit 5986 at any of the modules affected.

Chevrolet Tech Tip: Rough Running Engine, DTC P0300

Some customers may complain of a rough running engine and the check engine light is on. You may find DTC P0300 (Engine Misfire Detected) set along with a misfire and low compression in one or more cylinders.

What Techs Have To Worry About With GF-6 Oils

API’s newest GF-6 oil standard have recently been approved, we are now beginning to discover just exactly what future oil service may look like for shops.

Oxygen Sensor And Catalyst Efficiency

The catalyst efficiency monitor verifies that the catalytic converter is operating at a high enough efficiency rating to keep exhaust emissions within predetermined values. The PCM compares the signals from the upstream and downstream oxygen sensors to determine the state of the converter. These “tests” are called the readiness monitors.

Making A Living With A Scope

All technicians know more complex cars with more expensive modules and sensors are coming to shops so parts swapping is not usually an option.

Fuel: It’s The Tank, Not The Pump

One of the most basic procedures when replacing a fuel pump – and often the most overlooked – is inspecting the fuel tank.

Why Maintenance Matters

Although Car Care Month is typically celebrated twice a year in April and October, that doesn’t mean you should miss great opportunities to host impromptu car care clinics during the summer.

Auxiliary Water Pump Diagnostics

A car or truck comes into your shop with a complaint of poor heater performance. The driver complains that on cold mornings the heater will blow cold during the drive to work in rush hour traffic. The car is not overheating and the air is coming from the correct ducts. Your first reaction might be to install a new thermostat and inspect the heater core for a blockage. On the test drive, the system may perform great for you. Is the customer just cold blooded?