Adjusting the Grand Cherokee automatic transmission
Required materials:
* OBDII scanner
* Fuel pressure stabilizer
* Fuel pressure gauge
* Wires with alligator clips
* Wrench set
* Fresh transmission fluid filter
* Transmission fluid
Steps:
1. Preparing the car
* Place the car on a level surface.
* Provide access to the underside of the vehicle using a lift or jacks.
* Disconnect the negative terminal of the battery.
2. Reset transmission adaptations
* Connect the OBDII scanner to the vehicle’s diagnostic port.
* Enter the Powertrain Control Module (PCM).
* Perform the “Transmission Adaptations Reset” function.
3. Checking the level and pressure of the transmission fluid
* Check the transmission fluid level on a cold engine. The level should be at the COLD mark on the dipstick.
* Connect the fuel pressure gauge to the transmission fluid pressure test port.
* Start the engine and warm it up to operating temperature.
* When shifting gears at idle, the pressure should fluctuate between 25 and 35 pounds per square inch (PSI).
4. Transmission fluid pressure adjustment
* If the transmission fluid pressure is not within the specified range, the fuel pressure stabilizer must be adjusted.
* Use a set of wrenches to loosen the fuel pressure stabilizer mounting nut.
*Turning the fuel pressure regulator clockwise will increase the pressure, and turning it counterclockwise will decrease the pressure.
* Recheck the transmission fluid pressure until it is within the specified range.
5. Replacing the transmission fluid filter
* Remove the transmission pan.
* Replace the old transmission fluid filter with a new one.
* Reinstall the transmission pan.
6. Filling transmission fluid
* Fill with fresh transmission fluid through the dipstick hole.
*Add enough fluid to bring the level to the HOT mark on the dipstick.
7. Assembly
* Connect the negative terminal of the battery.
* Check all connections for leaks.
* Reset transmission adaptations again.
8. Check
* Start the car and let it idle for about 10 minutes.
* Shift gears at all speeds and check for smooth shifting.
* Check for transmission fluid leaks.