Application Notes for Toyota A340 Series

Overview

There are many variations of the Toyota A340 and identifying them can be difficult. It’s important to know which type you have before you purchase a transmission controller. While the model number can be A340, A341, A342, A343 these are all fundamentally the same transmission with following variations.

The important differences come down to the following areas:

Gear ratios - A340, A341, A342, A343 each have different ratio combinations.
2WD or 4WD - 2WD usually has an “E” suffix, 4WD usually as an “F” suffix.
Pressure control - cable control vs. electronic pressure control
Shift solenoids - 2 or 4 solenoids
Accumulator / timing control solenoid - none PWM solenoid
TCC solenoid - on/off vs. PWM solenoid
Temperature sensors - none, internal sensor, external sensor switch
Output speed sensor - many different pulse counts
Input speed sensor - none or 16 pulse/rev

Many of these internal differences are reflected in the number of terminals in the main valve body connector, but in some cases, a test with an ohmmeter is required to determine the exact model. Note that there have been completely hydraulic A340 variations known as A340H. These are not suitable for electronic controls and will not be covered here.

Shift Solenoids	TCC Solenoid	Pressure Control Solenoid	Accumulator Control Solenoid	Input Speed Sensor	Output Speed Sensor	Temp Sensor	Valve Body Connector	Notes
2	on-off	None	None	None	1, 4	External	3 cavity 3 wires	3,5,6
2	on-off	PWM	None	None	4, 12	External	8 cavity 5 wires	3,5
2	PWM	None	PWM	16	1, 4	External	6 cavity 6 wires	1,5
2	PWM	PWM	PWM	16	4	External	8 cavity 8 wires	1,5
2	PWM	PWM	PWM	16	4	Internal	10 cavity 10 wires	1,4
2	PWM	PWM	None	16	12	Internal	8 cavity 8 wires	1,4
4	PWM	PWM	PWM	16	12	Internal	12 cavity 12 wires	1,2

The O/D Direct Clutch Speed Sensor measures the speed of the sun gear of the overdrive planetary gearset. This is at transmission input shaft speed in all non-overdrive gears, and stopped (0 RPM) when in overdrive.
This version is the A340 30-40LS or “Aristo” and has a different case and bellhousing bolt pattern than other A340 variations. This transmission never came in a US spec vehicle, but appears in JDM imports.
Cable control valve bodies can be replaced with electronic pressure control valve bodies with some work.
Most of the transmissions with internal temperature sensors were fitted to pickup trucks or SUV’s and had a dashboard temperature gauge.
External temperature sensor versions were usually just a overtemperature switch in the cooler lines. HGM can supply a Delphi sensor that reads actual cooler temperature instead, or the sensor can be fitted to the transmission pan.
This transmission is functionally similar to the AW4.