Acura TSX / Honda Accord CL. Manual - part 939

engine. 

Fig. 72: Torque Converter Clutch Lock-up ON (Engaging Torque Converter Clutch) Fluid Flow 

Torque Converter Clutch Lock-up OFF (Disengaging Torque Converter Clutch) 

Fluid entering from the chamber between the torque converter cover and the torque converter clutch piston 
passes through the torque converter and goes out through the chambers between the turbine and the stator, and 
between the pump and the stator. As a result, the torque converter clutch piston moves away from the torque 
converter, and the torque converter lock-up clutch is released; torque converter clutch lock-up is OFF. 

Fig. 73: Torque Converter Clutch Lock-up OFF (Disengaging Torque Converter Clutch) Fluid Flow 

No Lock-up 

Shift solenoid valve E is turned OFF by the PCM, and shift solenoid valve E pressure (SE) is not applied to the 

 

2004 Acura TSX 

2004 AUTOMATIC TRANSMISSIONS Diagnosis - MCTA 5-Speed

  

 

lock-up shift valve. The lock-up shift valve stays to the right to uncover the torque converter pressure ports 
leading to the left side of the torque converter and releasing pressure from the right side of the torque converter. 
Torque converter pressure (92) changes to (94) at the lock-up shift valve, and enters into the left side of the 
torque converter to disengage the torque converter clutch. This keeps the torque converter clutch piston keeps 
away from the torque converter cover and the torque converter lock-up clutch is OFF. 

Fig. 74: No Lock-up Fluid Flow 

Partial Lock-up 

As the speed of the vehicle reaches the prescribed value, shift solenoid valve E is turned ON by the PCM, and 
shift solenoid valve E pressure (SE) is applied to the right side of the lock-up shift valve. The lock-up shift 

NOTE:

When used, "left" or "right" indicates direction on the hydraulic circuit.

 

2004 Acura TSX 

2004 AUTOMATIC TRANSMISSIONS Diagnosis - MCTA 5-Speed

  

 

valve is moved to the left side to switch the torque converter pressure (91) port, which goes to the right side of 
the torque converter, and the port of torque converter pressure (94) is released from the left side of the torque 
converter. Torque converter pressure (91) flows to the right side of the torque converter to engage the torque 
converter clutch. The PCM also controls the A/T clutch pressure control solenoid valve A to regulate A/T clutch 
pressure control solenoid valve A pressure (55) is applied to the lock-up shift valve and lock-up control valve. 
The position of the lock-up control valve depends on A/T clutch pressure control solenoid valve A pressure (55) 
and torque converter pressure released from the torque converter. The lock-up control valve controls the amount 
of torque converter clutch lock-up until fluid between the clutch piston and torque converter cover is fully 
released; the torque converter clutch is in partial lock-up condition. 

Fig. 75: Partial Lock-up Fluid Flow 

NOTE:

When used, "left" or "right" indicates direction on the hydraulic circuit.

 

2004 Acura TSX 

2004 AUTOMATIC TRANSMISSIONS Diagnosis - MCTA 5-Speed

  

 

Full Lock-up 

When the vehicle speed increases, the PCM sends a signal to A/T clutch pressure control solenoid valve A to 
increase A/T clutch pressure control solenoid valve A pressure (55), and the lock-up control valve is moved to 
the left by the increased pressure. Then increased converter pressure (94) from the left side of the torque 
converter is completely released at the lock-up control valve, and torque converter pressure (91) engages the 
torque converter clutch securely; the torque converter clutch is in full lock-up condition. 

Fig. 76: Full Lock-up Fluid Flow 

SHIFT LEVER MECHANISM 

NOTE:

When used, "left" or "right" indicates direction on the hydraulic circuit.

 

2004 Acura TSX 

2004 AUTOMATIC TRANSMISSIONS Diagnosis - MCTA 5-Speed