Diagnostics of automatic transmission FB15 Nissan Sunny

Tools and Equipment:

* OBD-II scanner
* Multimeter
* Automatic transmission fluid

Diagnosis steps:

1. Visual inspection:

* Inspect the automatic transmission for fluid leaks, damage or loose connections.
* Check the automatic transmission fluid level using the dipstick.

2. Reading fault codes:

* Connect the OBD-II scanner to the vehicle’s diagnostic port.
* Read fault codes related to automatic transmission.
* Write down the codes and their definitions.

3. Checking electrical connectors:

* Disconnect and reconnect all electrical connectors associated with the automatic transmission.
* Inspect connectors for corrosion, damage, or loose connections.
* Tighten all connector screws.

4. Checking the automatic transmission fluid pressure:

* Connect a multimeter to the automatic transmission fluid pressure test port.
* Start the engine and shift through all gears.
* Check the fluid pressure in all gears and compare it with the manufacturer’s specifications.

5. Checking automatic transmission solenoids:

* Using an OBD-II scanner, give the command to activate the automatic transmission solenoids.
* Listen for clicking sounds which indicate the solenoids are activating correctly.

6. Slip test:

* Accelerate the car to a speed of about 50 km/h and keep the accelerator pedal in a constant position.
* Monitor engine speed.
*If the RPM jumps sharply, this may indicate clutch or transmission slippage.

7. Automatic transmission adaptation reset:

* After correcting any problems with the automatic transmission, you may need to reset the automatic transmission adaptation.
*This can be done using an OBD-II scanner or by disconnecting the battery for a few minutes.

8. Reflashing the automatic transmission ECU:

* In some cases, it may be necessary to reflash the automatic transmission ECU.
* This requires special equipment and software, which is available at Nissan dealerships.

Notes:

*Always follow your specific vehicle’s service manual for exact instructions.
*If you are unsure of your diagnostic skills, consult a qualified mechanic.
* Automatic transmission repairs can be complex and expensive, so prompt diagnosis and service are critical to preventing serious problems.

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