Vehicle Body Electrical Accessories

The key to diagnosing a problem with an electric body control system is understanding how the system works. Knowing how the components work will help you correctly diagnose a failed component. Join industry veterans Jeff Taylor and Dom Sgambelluri for this look at "Vehicle Body Electrical Accessories.” We will highlight the significant changes made to the windshield wiper motor system throughout this lesson. A windshield wiper module controls the entire system. Requests for wiper activation are sent on the Local Interconnect Network or LIN Bus. Changes in technology change how we diagnose a fault in the system. Participants will be familiarized with activating components through scan tools, calibration and learn procedures, system overview and component operation.

Idle Start-Stop Technology

The Stop-Start system is used to improve fuel efficiency in stop-and-go driving. Turning off the engine under appropriate conditions at a traffic light helps reduce tailpipe emissions and save fuel that would otherwise be wasted idling the engine. When a driver comes to a red light, the engine shuts down while other components continue to run, including the air conditioning system, power steering, brakes and sound system.

The starter motor is upgraded with a high-performance electric motor and a stronger pinion engagement mechanism with reduced noise levels to support the increased number of engine starts. A sensor connected to the battery continually monitors the State of Charge and battery health. The Engine Control Module (ECM) uses this information to calculate if the battery conditions are sufficient for Stop-Start operation.

Start-Stop is a shared strategy among many modules using status information to determine what happens at the next stoplight. Since 2015, almost every major automaker has offered one or more models with idle Start-Stop control. For the technician, this adoption means that serial data communication bus and electrical diagnostics will be much more critical in the future.

EVAP System and Components

"EVAP System and Components" looks at the construction and function of the Evaporative Emission Control (EVAP) system, including the On-board Refueling Vapor Recovery (ORVR) system. We will examine individual components, including the charcoal canister, the purge and vent controls and the various sensors and switches. The lesson will describe how each component works and how they all work together as one system, and it will cover the basic EVAP system as well as the NVLD, DSIM and DMTL systems. Learn how the Powertrain Control Module (PCM) operates the EVAP system and checks for leaks and malfunctions. We will describe how a scan tool is used to diagnose trouble codes and to ensure the system is properly repaired before returning the vehicle to the customer.