Diagnostics

Diagnostics

Special Tool(s):

Diagnosing an electronically controlled automatic transmission is simplified by using the following procedures. One of the most important things to remember is that there is a definite procedure to follow. DO NOT TAKE SHORT CUTS OR ASSUME THAT CRITICAL CHECKS OR ADJUSTMENTS HAVE ALREADY BEEN MADE. Follow the procedures as written to avoid missing critical components or steps. By following the diagnostic sequence, the technician will be able to diagnose and repair the concern the first time.

On-Board Diagnostics With Diagnostic Tool

NOTE: For detailed instruction and other diagnostic methods using the diagnostic tool, refer to the diagnostic tool tester manual and Computers and Control Systems. These quick tests should be used to diagnose the powertrain control module (PCM) and should be carried out in order.

^ Quick Test 1.0 - Visual Inspection
^ Quick Test 2.0 - Set Up
^ Quick Test 3.0 - Key On, Engine off (KOEO)
^ Quick Test 4.0 - Continuous Memory
^ Quick Test 5.0 - Key On, Engine Running (KOER)
- Special Test Mode
- Wiggle Test
- Output Test Mode
- PCM Reset Mode
- Clearing DTCs
- OBD II Drive Cycle
^ Other Diagnostic Tool Features
For further information on other diagnostic testing features using the diagnostic tool, refer to Computers and Control Systems. Other diagnostic methods include the following:
- Parameter Identification (PID) Access Mode
- Freeze Frame Data Access Mode
- Oxygen Sensor Monitor Mode