The engine-ECU learns the relation between the suction control valve (linear solenoid valve) of the supply pump drive current and the fuel injection volume.
The learning value is calculated from the suction control valve drive current and the rail pressure sensor output voltage.
When the suction control valve or supply pump is replaced, therefore, this learning must be executed.
Re-learning is executed when the engine is idling after the learning value in the engine-ECU has been reset by the M.U.T.-III.


caution To prevent damage to M.U.T.-III, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting M.U.T.-III.

1.After the ignition switch is in "LOCK" (OFF) position, connect the M.U.T.-III to the diagnosis connector.
2.Turn the ignition switch to the "ON" position. (Do not start the engine.)
3.Select "MPI/GDI/DIESEL" from System select Screen of the M.U.T.-III.
4.Select "Special Function" from MPI/GDI/DIESEL Screen.
5.Select "Initialisation" from Special Function Screen.
6.Select Item No. 21 "Supply pump exchange service" from "Initialisation Screen and execute the initialisation of learning value.

  • Accelerator pedal: OFF (not depressed)
  • Engine coolant temperature: 60°C or higher
  • Fuel temperature: 30°C or higher
7.After initialising, run the engine at idle in the following conditions for 30 seconds.
8.Confirm that the Item No. 65 "High press. pump learned status" on M.U.T.-III Data List is "2".
note "2" indicates that the learning has completed.