Diagnostic Test Procedures

Finding the cause of a communication problem is not always easy or quick. However, the diagnostic test procedures have been designed to lead you through the steps necessary to find the cause as easily and quickly as possible.

- The diagnostic test procedures contain step by step instructions for how to determine the cause of a vehicle fault. Possible sources of the fault are checked and eliminated one by one.
- The diagnostic tests include a schematic of the electrical circuitry for the system, and illustrations of the system components and connectors to clarify the test steps.
- For instructions on performing test procedures, see "Diagnostic Test Procedures".

To successfully perform diagnostic testing, use the information and follow the procedures as presented in this section.

DIAGNOSTIC TEST PROCEDURES
A diagnostic test procedure is:

- a systematic method of checking the functioning of a vehicle control system to determine if it is operating normally.

Guidelines for Performing Diagnostic Test Procedures
All test procedures assume that Chrysler's DRBII diagnostic read-out box is being used. Refer to HELP 1 - Operation of the DRBII for Diagnostic Testing for instructions on connecting the DRBII to the diagnostic connector.

To properly perform diagnostic testing of body systems using the test procedures in this section, ALWAYS start with Test 1A. Starting with any other test may result in incorrect fault diagnosis.

^ Make sure the vehicle being tested has a fully charged battery.
^ The tests are presented in modified flowchart form.
- The first two columns contain instruction statements. Perform each instruction in order. Perform each instruction as stated.
- The third column contains diagnostic questions. Answer each question with a "yes" or "no" answer.
- The fourth column contains repair or replacement instructions. Perform only the repair/ replacement instruction(s) that follow from the "yes" or "no" answer to each question.
- To proceed from one process box to another, follow the direction of the lines between the boxes as indicated by the arrows.
- If a test is continued, an instruction is given in an arrow-shaped "box" to direct you to another test.

NOTE: Tests are identified by a number/letter combination, such as Test 1A or Test 5C. To avoid confusion between the number 1 and the letter "I" and between the number 0 and the letter "0", no test identifications use the letters "I" or "0".

^ Be careful when performing electrical tests so as to prevent accidental shorting of terminals. Such mistakes can damage fuses or components. Also, a second fault message could be set, making diagnosis of the original problem more difficult.
^ Use the DRBII voltmeter unless otherwise instructed to use an "external" voltmeter.

NOTE: Under no circumstances should a test lamp be used in place of a voltmeter.

^ Use the DRBII ohmmeter unless otherwise instructed to use an "external" ohmmeter. After each repair is completed, perform the Verification Test procedure Test VER-1).