Checking Rack Sensor System

CHECKING RACK SENSOR SYSTEM












[CHECK/1] Check harness at control unit end
1. Turn the ignition key switch OFF.
2. Measure the resistance between terminals (8) and (9), (9) and (21), (8) and (21) of connector [I-97-2].
3. Check the insulation of each terminal and the rack sensor body.







4. Judgement
- Resistance value normal -> rack sensor harness normal -> go to [CHECK/2]
- Resistance value abnormal -> check resistance of rack sensor body -> go to [CHECK/3]







[CHECK/2] Check output voltage of rack sensor
1. Start the engine and run the engine at idling speed.
2. Measure the voltage between terminal (2) (- end) and terminal (1) (+ end) of rack out connector [I-88] inside the control unit cover.







3. Judgement
- Output voltage normal -> rack sensor position normal -> carry out [CHECK/1] again or replace C.U.
- Output voltage abnormal -> replace injection pump assembly







[CHECK/1] Check rack sensor body
1. Measure the resistance between terminals (3) and (2), (2) and (1), (3) and (1) of connector [C-133].
2. Check the insulation of each terminal and the rack sensor body.







3. Judgement
- Resistance value is as specified -> go to [CHECK/4]
- Disconnection, short circuit, or resistance value is not as specified -> rack sensor abnormal -> replace injection pump

[CHECK/4] Check harness







1. Turn the ignition key switch OFF.
2. Refer to the table below and check for continuity, short circuit, and insulation between harness connector [C-133] of the rack sensor and harness connector [I-97-2] of the control unit.







3. Judgement
- If the harness is abnormal (disconnection, short circuit, etc.) -> repair or replace the harness
- If the harness is not abnormal -> improper output voltage of rack sensor or abnormality in control unit -> contact ZEXEL sales for repair

NOTE:
- If there is no abnormality in the harness or resistance value of the rack sensor, the rack sensor output voltage may be defective or the may be an abnormality in the control unit. However, the set condition cannot be re-enacted when the equipment is mounted on the machine, so it is difficult to check.
- After completing each operation, carry out troubleshooting with the diagnostic light and confirm that there is no abnormality.