BUS circuit testing on The Type 3 Composite Vehicle – ASE L1 Test Prep

ASE L1 Test Prep: BUS circuit testing on The Type 3 Composite Vehicle

The Advanced Engine

The Advanced Engine ­Performance Specialist (L1) test contains 50 scored questions focused on the diagnosis of general powertrain, computerized powertrain controls (including OBD II), ignition systems, fuel and air induction systems, emission control systems and I/M test failures. 
 Section B of the Task List on computerized powertrain controls states that you should be able to perform the following items on circuits:
• Voltage Drop
• Current Flow
• Continuity/Resistance
• Waveform Analysis
Many of the circuit testing questions relate to a sample vehicle using a composite ­powertrain control system featuring computerized engine control technology used by most manufacturers. This vehicle is described in the Composite Vehicle Type 3 Reference Booklet that is provided both before and at the time of testing. 
The Type 3 vehicle was introduced in 2006. This vehicle has several serial data buses and multiple modules. There will be question on the test concerning how different conditions like shorts, opens and changes in resistance can alter serial data bus traffic. You also have to be able to understand the test results from voltage drop, resistance and scope analysis. 
Most of all you need to understand how a serial data bus network shares information by just changing voltages over two wires.
Good luck! 

You May Also Like

Chassis Control Modules After Reconnecting Battery

To resolve the issue, fully disconnect the negative lead from the battery terminal.

Models: XJ/X351, XF/X250 with air suspension

Issue: If the battery supply to the vehicle is disconnected for any reason, the Chassis Control Module (also known as the Air Suspension Module or Suspension Module Integrated Suspension Control Module (CHCM) may not power-up correctly. As a result, a scan tool will report no communication with the CHCM module in several session screens. This will only affect a small percentage of cars and on an intermittent basis.

Mode $06 Misfire Diagnosis

Understanding why ‘Mode $06’ was developed and how it works to identify misfires.

ADAS Calibration Tips

Here are 10 tips to follow during ADAS Calibration.

Auxiliary Cooling Pumps

An auxiliary cooling pumps primary function is to circulate warm coolant to the heater core.

Do You Know The Cause Of A No-Spark Condition?

A no-spark condition could be the result of communication errors or missing data from a dead module.

Other Posts

Power Window Regulator and Motor Service

Power windows are great as long as they roll up and down when commanded to do so.

New Oil Specifications

Many 0W16 oils have a new donut certification mark on the bottle called API SN-PLUS and SN-PLUS Resource Conserving.

Solving Intermittent Overheating

New cooling systems anticipate and influence changes in coolant temperature.

Ignition Systems

The ignition coil is a very simple and robust circuit.