Diagnostic Notes
NOTE: Before beginning any diagnosis, familiarize yourself with the HELPFUL INFORMATION section. Helpful Information (Help 1-8)TIP: Be sure the vehicle being tested has a fully charged battery. If it does not, false trouble codes or errors may result.
Flow Of Diagnosis:
NOTE: For catalytic converter and feedback system to function properly, it is essential that vehicle is at operating temperature, (except when attempting to diagnose cold start or cold driveability problem).
ALL DIAGNOSIS SHOULD FOLLOW THESE STEPS
1. VERIFY COMPLAINT
2. EXTRACT CODES
3. PERFORM A VISUAL INSPECTION
4. CHECK FOR RELATED SYMPTOMS AND ISOLATE PROBLEM
5. REPAIR PROBLEM
6. VERIFY PROPER OPERATION
VERIFY CUSTOMER COMPLAINT
The first step in systematic diagnosis is to understand the customer's complaint and verify that it is not normal operation.
- Use the Vehicle Repair History And Driveability Worksheets In TECHNICAL/ MANAGEMENT SUPPORT to provide better communication between the customer and the mechanic.
- The vehicle repair history can provide explanations to unusual complaints which seem to elude normal troubleshooting attempts. Incorrect components or unapproved repairs can have subtle influences on seemingly unrelated systems.
- Check any Technical Service Bulletins that may apply to the vehicle being serviced.
EXTRACT TROUBLE CODES
Extracting trouble codes identifies any obvious problem areas and verifies operation of the on board diagnostic system.
- Diagnostic Trouble Codes are cleared whenever the Engine Controller or the battery is disconnected. Therefore, all fault codes should be read prior to any vehicle power interruption or troubleshooting.
- Diagnose and repair any fault code related problems before proceeding with further diagnosis.
PERFORM VISUAL INSPECTION:
A thorough visual inspection can save hours of diagnostic time.
- Many electrical problems can be seen with the naked eye, i.e. burned or melted insulation, blackened components etc..
CHECK FOR RELATED SYMPTOMS AND ISOLATE PROBLEM
Test components and systems to isolate cause of problem.
Avoid correcting symptoms without fixing the problem(s) causing the symptoms.
REPAIR PROBLEM
Perform needed repairs.
VERIFY PROPER OPERATION
Verify that repairs have fixed the complaint by performing verification test when possible.
If there is no verification test for the procedure used, attempt to operate the repaired system, and note operation.EXTRACT CODES
Begin electronic four speed automatic transaxle diagnosis by checking for Diagnostic Trouble Codes (DTC's), with a scan tool. SEE Powertrain Management/Computers and Control Systems/Testing and Inspection/Procedures. This will direct you to the specific test(s) for each DTC.
NOTE: If more than one trouble code exists, priority should be given to the most recent code set.
CCD BUS PROBLEMS
- If there is a CCD bus bias or communication problem, trouble codes might not be accessible until the problem is fixed.
- The following list of possible CCD bus problems may be displayed by the scan tool:
- Open or short to ground or battery (B+), in either or both CCD bus wires (pins 4 and 43)
- Open or short to ground or battery (B+) in either or both TCM bias wires
- Open or short to ground or battery (B+) in the diagnostic connector bus wires
- Internal failure of any control module connected to the bus
NOTE: The COD bus should measure +2.5 volts on CCD(+) and -2.5 volts on CCD(-).
DIAGNOSTIC CHARTS
After extracting DTC's, use the corresponding Diagnostic Charts to diagnose the problem. Testing and Inspection
MALFUNCTIONS MAY BE CAUSED BY THESE GENERAL CONDITIONS:
- Poor Engine Performance
- Improper Adjustments
- Hydraulic Malfunctions
- Mechanical Malfunctions
- Electronic Malfunctions
PRELIMINARY CHECKS
NOTE: Always begin diagnosis of these problems by checking the easily accessible variables: fluid level and condition, gearshift cable adjustment.
- If a problem is found during the preliminary checks, correct the problem, and determine whether more diagnosis is necessary by performing a road test.
- If the problem exists after the preliminary checks and corrections are completed, perform hydraulic pressure checks.
DIAGNOSIS OF TROUBLE CODES:
1. Visual Inspection
- A careful and thorough visual inspection may quickly identify the cause of a malfunction and eliminate the need for additional diagnostic procedures.
- Always begin diagnosis of vehicle codes with a visual inspection. If the code is not resolved by the visual inspection, perform the diagnostic test(s). Initial Inspection and Diagnostic Overview
2. Diagnostic Tests
- To successfully perform diagnostic testing, follow the procedures as presented.
- Always begin diagnostic testing with Test 1A. This will direct you to the specific test(s) that must be performed in response to the specific vehicle code.
- Perform the test for the most current code.
- Each specific code is diagnosed by following a specific testing sequence. It is not necessary to perform all of the tests in this book to diagnose an individual code.
3. Verification Test
- Verify system operation, after the cause of a code has been found and repaired, by performing TEST VER-1. Verification Tests
NOTE: These diagnostic test procedures were designed for use with Chrysler's DRBII diagnostic read-out box. It should be possible to perform the same tests using an equivalent scan tool, by following the manufacturer's instructions.
NOTE: Follow the FLOW OF DIAGNOSIS for the correct diagnostic sequence. Flow of Diagnosis