Automatic transmission diagnostics
Tools and Equipment:
* OBD-II scanner
* Transmission fluid pressure gauge
* Transmission fluid thermometer
* Diagnostic software
Diagnostic stages:
1. Reading Trouble Codes (DTC)
* Connect the OBD-II scanner to the vehicle’s diagnostic connector.
*Read transmission related trouble codes.
* Write down any codes found and their descriptions.
2. Checking the level and condition of the transmission fluid
* Remove the transmission oil dipstick.
* Check the fluid level and color.
* The liquid should be red or green in color, not dark or brown.
* Check for metal particles, clots or foamy liquid.
3. Transmission fluid pressure measurement
* Connect the pressure gauge to the transmission pressure port.
* Start the engine and switch the box to different modes.
* Record pressure readings under various operating conditions.
*Compare readings with manufacturer’s specifications.
4. Transmission fluid temperature measurement
* Insert a thermometer into the temperature port in the transmission.
* Start the engine and switch the box to different modes.
* Record temperature readings under different operating conditions.
*Compare readings with manufacturer’s specifications.
5. Diagnostic software data analysis
*If diagnostic software is available, connect it to the transmission.
* Collect transmission performance data including:
* Transmission fluid pressure
*Transmission fluid temperature
* Engine speed
*Vehicle speed
* Analyze data to identify any anomalies or faults.
6. Troubleshooting
* Once the fault areas have been identified, begin troubleshooting.
*This may include changing the transmission fluid, replacing filters, or repairing or replacing transmission components.
Note: Diagnosing an automatic transmission can be a complex process requiring specialized tools and knowledge. It is recommended that you contact a certified mechanic for accurate diagnosis and repair.