Basics of the Lock Up Solenoid Assembly

The solenoid assembly is made up of two solenoids. One is the torque converter clutch solenoid and the other is the shift solenoid A.

The solenoid assembly is located on the exterior of the transmission housing and bolted down by 3 bolts. Photo 1 of 2 and 2 of 2, in the image viewer, show the location of the assembly on the transmission itself.

Here's some basic, and I stress 'basic', info on both solenoids (that make up the assembly):

Torque converter clutch solenoid valve:

PCM activates the solenoid as your Honda reaches a prescribed speed.

Solenoid is activated only in 3rd and 4th gears only.

When ‘On’, causes the lock up clutch to engage inside the torque converter.

The torque converter clutch solenoid is also known as:

Lock-up control solenoid.

TCC solenoid.

The lock-up control solenoid is identified in image 2 of 2 (in the image viewer).

Shift solenoid valve A:

Works in conjunction with shift solenoid B and shift solenoid C.

Is activated by the PCM.

In D3 or D4, the solenoid is:

1st gear: ON.

2nd gear: ON.

3rd gear: ON.

Shift solenoid A is identified in image 2 of 2.

OK, let's get testing...

START HERE: Lock Up Solenoid Assembly Tests

Troubleshooting the lock-up solenoid assembly isn't hard. There are two basic tests for each solenoid that makes up the pack.

Here's a brief description of the 4 tests in this tutorial:

Resistance testing shift solenoid A..

This test simply involves measuring the resistance of shift solenoid A and comparing the value with the factory spec of 12-25 Ohms.