Checking automatic transmission solenoids with a multimeter for Subaru cars
Required tools:
* Multimeter
* Set of open-end wrenches
*Paper towels
* Dielectric gloves (recommended)
Warnings:
*Before starting work, make sure the vehicle is parked on a level surface and the parking brake is set.
*Transmission fluid may be hot, so be careful when draining it.
* Use dielectric gloves to avoid electric shock.
Procedure:
1. Definition of solenoids:
* Find the gearbox and remove the automatic transmission pan.
* Locate the solenoids, they are usually located on the valve body.
* Identify each solenoid according to the vehicle wiring diagram.
2. Disconnecting electrical connectors:
* Disconnect the electrical connectors from the solenoids.
* Wipe connectors and solenoids with paper towels to remove any dirt or oil.
3. Resistance check:
* Set the multimeter to resistance measurement mode.
*Connect the black lead of the multimeter to the solenoid body.
*Connect the red lead of the multimeter to the solenoid terminal.
* Read the resistance value on the multimeter display.
4. Expected resistance values:
*Resistance values may vary depending on the Subaru model, but they are generally in the following range:
* Torque converter lock-up solenoid: 10-20 ohms
* Shift Solenoid: 15-25 ohms
* Pressure control solenoid: 5-15 ohms
5. Evaluation of results:
*If the resistance is within the expected range, the solenoid is good.
*If the resistance is too high (infinity) or low (0 ohms), the solenoid is bad and needs to be replaced.
6. Short circuit test:
* Set the multimeter to resistance measurement mode.
*Connect both leads of the multimeter to the solenoid terminals.
*If the multimeter shows resistance close to zero, this indicates a short circuit in the solenoid.
7. Reassembly:
* After checking the solenoids, reconnect the electrical connectors and install the automatic transmission pan.
*Add transmission fluid to the recommended level.