Check for module communication errors (including CAN/BUS systems) using a scan tool

Lesson Plan for

AUT 186-187/AUT 292

Automotive Service Technology Section C/Automotive Special Problems

Course HS Title: / Automobile Service Technology/Special Problems / Program:
KCTCS Courses included in HS Title: (Lesson is prepared for course highlighted.)
KCTCS Course No. / KCTCS Course Title
Introduction/Context / This lesson will instruct the student on how to check for module communication errors (including CAN/BUS systems) using a scan tool. Knowledge of these techniques and the skills required to correct problems associated with this task are necessary for a student to acquire if they wish to compete for high paying, high skilled jobs in an Automotive Repair Facility. Entry level technicians need to be able to perform this task to 100% accuracy. Incorrectly performing this task can lead to an automobile accident or create customer satisfaction issues.
Prepared By / School / Date:
Grade Level / No. Students / No.IEP's: / Lesson Length:
Task
Check for module communication errors (including CAN/BUS systems) using a scan tool.
No. / Objective
1 / Given the proper tools and instruction, the student will be able to check for module communication errors (including CAN/BUS systems) using a scan tool, and pass a written test covering the task with 100% accuracy.

Connections:

Skills Standards:
OH 001
OH 002
OH 003
OD 002
OD 003
OD 005
Common Core Technical Standards:
TD-SYS-2
New Common Core Standards:
RST 11-12.2
RST 11-12 3
A-CED-4,
N-Q-1

INSTRUCTIONAL MATERIALS/TECHNOLOGY

Teacher Designed Materials and Other Handouts

Textbooks and Workbooks

Author / Title/ISBN No. / Edition / Publisher / Pages
Tim Gilles / Automotive Service Inspection, Maintenance and Repair / third / Thomson Delmar / 759-762
Barry Hollenmbeak / Automotive Electricity and Electornics / Fourth / Thomson Delmar / 418


Web Addresses

Title / Publisher / URL
Today's Class / Melior / www.todaysclass.com


Equipment

Quantity / Item / Source
As Needed / Scan Tool / Various
As Needed / Universal Breakout Box J1962 / Various


Content/Presentation/Demonstration Outline

Instruct students that Bus/CAN (Controller Area Network) diagnosis is similar to other electrical system diagnoses. Tell them to verify the complaint, look for related symptoms and analyze them, and troubleshoot in a logical sequence. Cover the basics. If a module is not communicating, teach students to check for a loss of sufficient battery voltage or a poor ground.
Explain to students that Bus systems use the DLC (Data Link Connector) to communicate with the scan tool. SAE (Society of Automotive Engineers) Standard J1962 specifies a DLC connection that will work on any OBD II vehicle. Let them know that the standard applies not only to scan tools. A universal breakout box that connects in series between the scan tool and the DLC is also available. A breakout box provides a means of testing voltages and resistances in individual circuits accessed by the DLC.
Remind students that P-codes are those related to the powertrain. In a similar manner, network communication fault codes are called U-codes and body system faults are called B-codes. Most modules can set a U-code when an abnormal condition is sensed. Explain that this can include a failure of the bus or a problem with a module. In addition a module expecting a message on the bus from another module might set a U-code and a B-code. Let students know that the scan tool lists the status of a DTC as active if it is a current condition. If the condition no longer exists, the scan tool lists the condition as a stored code.
Explain that some scan tools have a vehicle module scan feature. This queries all of the modules and lists any that did not reply. Tell students that if a scan tool cannot communicate with the PCM, check the service literature and review the wiring diagram to help analyze the cause of the problem. Have students look for variations and commonalities in network construction that can help you understand a simple or widespread fault. Data are shared on the network, so tell students to look for something in common among related systems.
Teach students that CAN systems usually use more than one class of network. Vehicles that utilize Controller Area Network (CAN) bus systems will generally have two or three different CAN systems. Let students know that the vehicle body systems will communicate over the medium speed CAN B network. Those systems such as engine controls and antilock brakes that require data at a faster rate will communicate on the CAN C bus. Tell students that beginning in the 2005 model year, manufacturers have started migrating to the new requirement for using a CAN bus network for diagnostics (often referred to as diagnostic CAN C).
Diagnostic CAN C works with the scan tool, which will help you identify which network you are working on (CAN B, for instance). The CENTRAL GATEWAY MODULE is the common component to all of the networks and can provide a DTC pointing them to a faulty circuit or component. Tell students that if they cannot communicate with the central gateway module, the CAN C circuit is the problem.
Instruct students on how to determine whether there is a total or partial failure in the bus. In the case of a total bus failure, there will be a short to voltage or ground. Let them know that the breakout box can be used to test voltages and resistance. Also, tell students that service information will provide steps for solving a network problem.
Instructor can use the following information as an example of network troubleshooting for the students. CAN B networks can still operate in single-wire mode (either + or -) when there is an open in a circuit, so there might not be a symptom. When the other circuit is shorted to ground (the one not listed in the fault), the faulty module will no longer be able to communicate and all other modules on the network will go into single-wire mode. Use the scan tool with a jumper wire shorted to ground to determine which module is not communicating. Tell students that the location of the fault will be between the bus and the module.


Applications/Practice

1 / Refer to content


Evaluation and feedback Prior to Testing or Lab Work

1 / Objective 1. / Formative assessment / Instructor will observe students as they practice the procedure to assure correct procedure and safety practices are being followed. A checklist will be utilized to chart student progress on the task. Questioning techniques will be utilized as necessary to demonstrate student comprehension / Adaptations and/or accommodations for special needs students will be added if required.


STUDENT ASSESSMENT:(Assess student progress with performance criteria.)

1 / Objective 1 / Summative assessment / written test questions on stated objective / adaptation and / or accommodations for special needs students will be added if required
IMPACT--Reflection/Analysis of Teaching and Learning: (How did students’ progress in relation to the state objectives? Was the instruction successful? Analyze samples of student work particularly that which is unsatisfactory, for the purpose of planning further instruction.)
REFINEMENT--Lesson Extension and Follow-up: (To be filled in as the lesson is modified during initial planning and/or during the teaching learning process.)