JATCO AUTO BOX - System Overview

The JATCO (Japanese Automatic Transmission Company) who also manufacture a range of gearboxes also manufacture this ECU. The case of this ECU is unbelievably cheap and basic considering what it does.

SM004 - JATCO AUTO BOX - System Help file

Version 1.22

JATCO AUTO BOX - Known Fitments

Vehicle makes, models and variants known or believed to be using this vehicle system, required diagnostic lead and degree of known compatibility. Vehicle Make Vehicle Model Vehicle Variant Diagnostic Lead Land Rover Freelander All Auto Black OBDII Lead Rover Rover 75 All Auto Black OBDII Lead Rover Rover 75 Tourer All Auto Black OBDII Lead Rover Rover 800 Auto KV6 Black OBDII Lead Rover Rover 45 All Auto Black OBDII Lead

JATCO AUTO BOX - Physical Details

JATCO AUTO BOX - Pin Outs

Details of the pin usage for the ECU connector(s).   1 Diagnostic socket 2 Unused 3 24/B duty gearbox solenoid 4 24/B timing gearbox solenoid 5 Vehicle speed sensor 6 Unused 7 Selector 2nd 8 Selector 1st 9 Ground 10 RDCN timing gearbox solenoid 11 Unused 12 Engine management ECU can bus 13 ABS ECU can bus 14 Shift B gearbox solenoid 15 Shift A gearbox solenoid 16 Lock up duty gearbox solenoid 17 Gearbox solenoid feed 18 Line pressure duty gearbox solenoid 19 Steptronic Switches 20 Sensor feed 21 Intermediate sensor 22 Unused 23 Unused 24 Turbine sensor 25 Selector neutral 26 Selector reverse 27 Selector drive 28 Unused 29 Unused 30 Selector park 31 Unused 32 Unused 33 Engine management ECU can bus 34 ABS ECU can bus 35 Unused 36 12 volts power supply 37 Steptronic switches 38 Ground 39 Fuel temperature sensor 40 Unused 41 Steptronic lamp 42 Unused 43 Brake pedal switch 44 Unused 45 Selector 4th 46 Unused 47 Unused 48 Unused 49 Cruise control ECU 50 Starter inhibitor/reverse light 51 Unused 52 Shift C gearbox solenoid 53 Low clutch timing solenoid valve - output 54 12 volts power supply

SM004 - JATCO AUTO BOX - Diagnostic Capabilities (Read Fault Codes)

Reads the fault code memory. The ECU can self detect up to 32 different problems with itself, its wiring and its associated sensors, storing the respective code if it detects any malfunction or reading outside of pre defined acceptable limits. Not all stored faults may cause the fault warning lamp to illuminate.

SM004 - JATCO AUTO BOX - Diagnostic Capabilities (Clear Fault Codes)

This function diagnostically clears the fault code memory.

SM004 - JATCO AUTO BOX - Diagnostic Capabilities (Settings)

Values, configuration settings, and other stored information which can be read from the ECU, edited and then rewritten back. Read settings can also be stored as a standard HTML page for reference. These pages can then later be re loaded and re written back to the ECU. Please note that some values may be read only due to the fact that they are supplied from the ECU's ROM or are internally calculated. Hardware number: This number is calculated from the internally stored hardware number. Software number: This is an internal number which denotes the base software of the ECU. In conjunction with other codes, this helps trace any production problems back to the exact source so that they can be quickly rectified. This code is, therefore, only of use in the event of a production / recall problem. Assembly Number: This is a number which is assigned during production. ETC Hardware number: This number is calculated from the internally stored ETC Hardware number. ETC number: This number is calculated from the internally stored ETC number. Coding index: This number is reserved to denote any minor revisions to the core coding of the Jatco ECU. Vin: This is the vehicle's identification number. Programmed date: This code is the day/month/year of the last programming date.

SM004 - JATCO AUTO BOX - Diagnostic Capabilities (Inputs)

Realtime live display of the information the electronic control unit of the selected vehicle system is currently deriving from its input sensors. Engine speed: This reading shows the engine speed in rpm. This value is transmitted from the engine ECU via the CAN bus. Turbine speed: This reading shows the internal transmission turbine speed. This signal is used to ensure the correct gear is used. Intermediate speed: This reading shows the internal transmission intermediate speed. This signal is used to ensure the correct gear is used. Output speed: This reading shows the gearbox output shaft speed. Indexed torque: This is the currently produced engine torque. This value is from the engine management ECU via the CAN bus. ATF Temperature: Automatic Transmission Fluid temperature. The reading shows the ATF temperature in degrees centigrade. If this temperature rises above 120 the ECU requests that the engine ECU turns the cooling fans on. Coolant Temperature: This is the current engine coolant temperature in degrees centigrade. Line pressure Duty ratio %: This is the pressure percentage of the transmission fluid. This value will drop as the temperature increases. Lock up pressure duty ratio %: This value is used when the ECU decides to lock the torque converter. This decision is made by the ECU monitoring the vehicle speed and throttle angle. 2/4 brake pressure duty ratio %: This value is the 2/4 brake duty ratio. Throttle position %: This is the amount of throttle being requested in %. Shift up switch: This shows the state of the shift up input. If you push the gear selector forward the input will then be on. Shift down switch: This shows the state of the shift down input. If you push the gear selector backward the input will then be on. Brake switch: This shows the state of the brake switch. This signal is received from the ABS ECU via the CAN bus. Sport switch: This shows the state of the sport mode input. Faults: This shows if there are any faults stored in the ECU. ATF over temperature: Automatic Transmission Fluid over temperature switch. This reading shows the cooling fan request. If the ATF temperature is above 120 degrees centigrade the switch will be on. Ignition switch: This is the state of the ignition switch. This signal is received from the engine management ECU via the CAN bus. Cruise input: This reading shows the state of the cruise control. If the cruise control input is on (ACTIVE) the ECU reduces the amount of unnecessary gear shifts. Shift solenoid A: This reading shows the current state of the solenoid. Shift solenoid B: This reading shows the current state of the solenoid. Shift solenoid C: This reading shows the current state of the solenoid. Low clutch solenoid: This status is used to control the engagement of 1st gear. Reduction solenoid: This status is used in shifts between 4th and 5th gears. Brake solenoid: This status is used during kick down shifts between 4th and 2nd. Current gear: This status shows the current or target gear. Selector gear: This status shows the current selector position. Driving mode: This status shows the current driving mode (manual, sport or normal). Torque with override: This shows the actual engine torque as a percentage of the maximum value as it is received from the engine management via the CNA bus. The value is used to control gear shift scheduling. This value does include frictional losses and torque reduction requests.

SM004 - JATCO AUTO BOX - Diagnostic Capabilities (Outputs)

Shift solenoid A: This function drives the Shift solenoid A ON for ten seconds. Shift solenoid B: This function drives the Shift solenoid B ON for ten seconds. Shift solenoid C: This function drives the Shift solenoid C ON for ten seconds. All shift solenoids off: This function drives all the Shift solenoids OFF for ten seconds. All other solenoids off: This function drives all the other solenoids OFF for ten seconds. Line pressure solenoid: This function drives the Line pressure solenoid ON for ten seconds. Brake duty solenoid: This function drives the Brake duty solenoid ON for ten seconds. Reduction solenoid: This function drives the Reduction solenoid ON for ten seconds. Clutch solenoid: This function drives the Clutch solenoid ON for ten seconds. Brake timing solenoid: This function drives the Brake timing solenoid ON for ten seconds.