Preliminary Testing and Diagnosis

Before any diagnostic testing is done on a vehicle some preliminary checks must be performed. Be sure to write down any findings, especially any DTCs, for future reference.
1. Know and understand customer's concern.
2. Verify that digital TR sensor is properly adjusted in NEUTRAL.
3. Verify customer concern:
- Upshift
- Downshift
- Coasting
- Engagement
If concern involves noise or vibration, does it relate to any of the following:
- Rpm
- Vehicle speed
- Shift
- Gear
- Range
- Temperature
4. Vehicle must be at normal operating temperature.
5. Check transmission fluid level and condition.
6. Check for the following items:
- Vehicle modifications
- Electronic add-on items
- Leaks
- Linkage adjustments
7. Check TSBs for related information.
8. Perform complete On-Board Diagnostics (OBD) or both KOEO and KOER.
9. Record all DTCs.
10. Repair all non-transmission DTCs.