[13B] MULTIPORT FUEL INJECTION (MPI) <4G64> - - TROUBLESHOOTING - CHECK AT THE ECU TERMINALSPRINT PAGE / INDEX / PRIOR / NEXT
CHECK AT THE ECU TERMINALS
TERMINAL VOLTAGE CHECK CHART
       
    1. Connect a needle-nosed wire probe to a voltmeter probe.
    1. Insert the needle-nosed wire probe into each of the engine-A/T-ECU connector terminals from the wire side, and measure the voltage while referring to the check chart.
      2. NOTE: 
      • Make the voltage measurement with the engine-A/T-ECU connector connected.
      • You may find it convenient to pull out the engine-A/T-ECU to make it easier to reach the connector terminals.
      • The checks can be carried out off the order given in the chart.
       CAUTION
       Short-circuiting the positive (+) probe between a connector terminal and earth could damage the vehicle wiring, the sensor, engine-A/T-ECU or all of them. Be careful to prevent this!
    1. If voltmeter shows any division from standard value, check the corresponding sensor, actuator and related electrical wiring, then repair or replace.
    1. After repair or replacement, recheck with the voltmeter to confirm that the repair has corrected the problem.
    Engine-A/T-ECU Connector Terminal Arrangement
       
    Terminal No.
    		 Check item
    		 Check condition (Engine condition)
    		 Normal condition
    1
    		 No. 1 injector
    		 While engine is idling after having warmed up, suddenly depress the accelerator pedal.
    		 From 11 - 14 V, momentarily drops slightly
    9
    		 No. 2 injector
    24
    		 No. 3 injector
    2
    		 No. 4 injector
    6
    		 EGR control solenoid Valve
    		 Ignition switch: "ON"
    		 System Voltage
    While engine is idling, suddenly depress the accelerator pedal.
    		 From system voltage, momentarily drops
    8
    		 Alternator G terminal
    • Engine: Warm, idle (radiator fan: OFF)
    • Headlamp: OFF → ON
    • Stop lamp: OFF → ON
    • Rear defogger switch: OFF → ON
    		 Voltage increases by 0.2 - 3.5 V
    11
    		 Ignition coil - No. 1, No. 4
    		 Engine: 3,000 r/min
    		 0.3 - 3.0 V
    12
    		 Ignition coil - No. 2, No. 3
    14
    		 Stepper motor coil <A1>
    		 Engine: Soon after the warmed up engine is started
    		 System voltage ⇔ 0 V (Changes repeatedly)
    28
    		 Stepper motor coil <A2>
    15
    		 Stepper motor coil <B1>
    29
    		 Stepper motor coil <B2>
    18
    		 Fan controller
    		 Radiator and condenser fan is not operating
    		 0 - 0.3 V
    Radiator and condenser fan is operating
    		 0.7 V or more
    19
    		 Air flow sensor reset Signal
    		 Engine: Idling
    		 0 - 1 V
    Engine: 3,000 r/min
    		 6 - 9 V
    20
    		 Fuel pump relay
    		Ignition switch: ON
    		 System voltage
    Engine: Idling
    		 1 V or less
    21
    		 A/C relay
    • Engine: Idling
    • A/C switch: OFF → ON (A/C compressor is operating)
    		 System voltage or Momentarily 6 V or more → 1 V or less
    22
    		 Engine warming lamp
    		 Ignition switch: "LOCK" (OFF) → "ON"
    		 1 V or less → System voltage (After several seconds have elapsed)
    41
    		 Power supply
    		 Ignition switch: "ON"
    		 System voltage
    47
    43
    		 Tachometer signal
    		 Engine: 3,000 r/min
    		 0.3 - 3.0 V
    44
    		 Engine coolant temperature sensor
    		 Ignition switch: "ON"
    		 When engine coolant temperature is -20°C
    		 3.9 - 4.5 V
    When engine coolant temperature is 0°C
    		 3.2 - 3.8 V
    When engine coolant temperature is 20°C
    		 2.3 - 2.9 V
    When engine coolant temperature is 40°C
    		 1.3 - 1.9 V
    When engine coolant temperature is 60°C
    		 0.7 - 1.3 V
    When engine coolant temperature is 80°C
    		 0.3 - 0.9 V
    45
    		 Crank angle sensor
    		 Engine: Cranking
    		 0.4 - 4.0 V
    Engine: Idling
    		 1.5 - 2.5 V
    46
    		 Sensor impressed voltage
    		 Ignition switch: "ON"
    		 4.9 - 5.1 V
    49
    		 Control relay (Power supply)
    		 Ignition switch: "LOCK" (OFF)
    		 System voltage
    Ignition switch: "ON"
    		 1 V or less
    52
    		 Power steering fluid pressure switch
    		 Engine: Idling after warming up
    		 When steering wheel is Stationary
    		 System voltage
    When steering wheel is turned
    		 1 V or less
    54
    		 Alternator FR terminal
    • Engine: Warm, idle (radiator fan: OFF)
    • Headlamp: OFF → ON
    • Stop lamp: OFF → ON
    • Rear defogger switch: OFF → ON
    		 Voltage decreases
    55
    		 Barometric pressure sensor
    		 Ignition switch: "ON"
    		 Altitude: 0 m
    		 3.8 - 4.2 V
    Altitude: 600 m
    		 3.5 - 3.9 V
    Altitude: 1,200 m
    		 3.3 - 3.7 V
    Altitude: 1,800 m
    		 3.0 - 3.4 V
    56
    		 Camshaft position sensor
    		 Engine: Cranking
    		 0.4 - 3.0 V
    Engine: Idling
    		 1.5 - 3.0 V
    58
    		 Ignition switch - ST
    		 Engine: Cranking
    		 8 V or more
    61
    		 A/C load signal
    		 Refer to GROUP 55A - Troubleshooting - Check at ECU Terminal
    62
    		 A/C pressure sensor
    • Engine: Idling
    • A/C switch: ON
    		 When A/C is "Maximum COOL" condition (when the load by A/C is high)
    		 2.2 V or more
    When A/C is "Maximum HOT" condition (when the load by A/C is low)
    		 1.8 V or less
    64
    		 Intake air temperature sensor
    		 Ignition switch: "ON"
    		 When intake air temperature is -20°C
    		 3.8 - 4.4 V
    When intake air temperature is 0°C
    		 3.2 - 3.8 V
    When intake air temperature is 20°C
    		 2.3 - 2.9 V
    When intake air temperature is 40°C
    		 1.5 - 2.1 V
    When intake air temperature is 60°C
    		 0.8 - 1.4 V
    When intake air temperature is 80°C
    		 0.4 - 1.0 V
    65
    		 Air flow sensor
    		 Engine: Idling
    		 2.2 - 3.2 V
    Engine: 2,500 r/min
    66
    		 Backup power supply
    		 Ignition switch: "LOCK" (OFF)
    		 System voltage
    71
    		 Mixture adjusting Screw (Variable Resistor) <Vehicles without catalytic converter>
    		 Ignition switch: "ON"
    		 1 - 4 V
    78
    		 Throttle position sensor
    		 Ignition switch: "ON"
    		 Set throttle valve to idle Position
    		 0.535 - 0.735 V
    Fully open throttle valve
    		 4.4 - 5.3 V
    83
    		 A/C switch
    		 Engine: Idling
    		 Turn the A/C switch OFF
    		 1 V or less
    Turn the A/C switch ON (A/C compressor is operating)
    		 System voltage
    98
    		 Ignition switch - IG
    		 Ignition switch: "ON"
    		 System voltage
    CHECK CHART FOR RESISTANCE AND CONTINUITY BETWEEN TERMINALS
    1. Turn the ignition switch to "LOCK" (OFF) position.
    1. Disconnect the engine-A/T-ECU connector.
    1. Measure the resistance and check for continuity between the terminals of the engine-A/T-ECU harness-side connector while referring to the check chart.
      2. NOTE: 
      • When measuring resistance and checking continuity, a harness for checking contact pin pressure should be used instead of inserting a test probe.
      • Checking need not be carried out in the order given in the chart.
       CAUTION
       If the terminals that should be checked are mistaken, or if connector terminals are not correctly shorted to earth, damage may be caused to the vehicle wiring, sensors, engine-A/T-ECU and/or ohmmeter.
      Be careful to prevent this!
    1. If the ohmmeter shows any deviation from the standard value, check the corresponding sensor, actuator and related electrical wiring, and the repair or replace.
    1. After repair or replacement, recheck with the ohmmeter to confirm that the repair or replacement has corrected the problem.
    Engine-A/T-ECU Harness Side Connector Terminal Arrangement
       
    Terminal No.
    		 Inspection item
    		 Normal condition (Check condition)
    1 - 41
    		 No. 1 injector
    		 13 - 16 Ω (At 20°C)
    9 - 41
    		 No. 2 injector
    24 - 41
    		 No. 3 injector
    2 - 41
    		 No. 4 injector
    6 - 41
    		 EGR control solenoid valve
    		 29 - 35 Ω (At 20°C)
    14 - 41
    		 Stepper motor coil (A1)
    		 26 - 33 Ω (At 20°C)
    28 - 41
    		 Stepper motor coil (A2)
    15 - 41
    		 Stepper motor coil (B1)
    29 - 41
    		 Stepper motor coil (B2)
    42 - Body earth
    		 ECU earth
    		 Continuity (0 Ω)
    48 - Body earth
    44 - 57
    		 Engine coolant temperature sensor
    		 14 - 17 kΩ (When coolant temperature is -20°C)
    5.1 - 6.5 kΩ (When coolant temperature is 0°C)
    2.1 - 2.7 kΩ (When coolant temperature is 20°C)
    0.9 - 1.3 kΩ (When coolant temperature is 40°C)
    0.48 - 0.68 kΩ (When coolant temperature is 60°C)
    0.26 - 0.36 kΩ (When coolant temperature is 80°C)
    64 - 57
    		 Intake air temperature sensor
    		 13 - 17 kΩ (When intake air temperature is -20°C)
    5.3 - 6.7 kΩ (When intake air temperature is 0°C)
    2.3 - 3.0 kΩ (When intake air temperature is 20°C)
    1.0 - 1.5 kΩ (When intake air temperature is 40°C)
    0.56 - 0.76 kΩ (When intake air temperature is 60°C)
    0.30 - 0.42 kΩ (When intake air temperature is 80°C)
    [13B] MULTIPORT FUEL INJECTION (MPI) <4G64> - - TROUBLESHOOTING - CHECK AT THE ECU TERMINALSPRINT PAGE / INDEX / PRIOR / NEXT
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