CHECK AT THE ECU TERMINALS


1.Disconnect the engine-ECU connector B-16, B-17 and B-18, and connect the check harness special tool MB996206, MB996207 and MB996208 among the engine-ECU connectors.
2.Measure the voltage between each check harness connector terminal and check harness connector earth terminal (No. 11 or No. 12).
3.Connect a needle-nosed wire probe to a voltmeter probe.
4.Referring to the check sheet, insert the micromini probe into the check harness connector and measure the voltage.
note
  1. You may find it convenient to pull out the engine-ECU to make it easier to reach the connector terminals.
  2. 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-ECU or all of them. Be careful to prevent this!
5.If voltmeter shows any division from standard value, check the corresponding sensor, actuator and related electrical wiring, then repair or replace.
6.After repair or replacement, recheck with the voltmeter to confirm that the repair has corrected the problem.
TERMINAL VOLTAGE CHECK CHART
Terminal No.
 Check item
 Check condition (Engine condition)
 Normal condition
7
 Power supply voltage applied to accelerator pedal position sensor (main)
 Ignition switch: ON
 4.9 - 5.1 V
16
 Exhaust gas temperature sensor
 Ignition switch: ON
 When DPF temperature is 25°C
 Approximately 4.8 V
18
 Accelerator pedal position sensor (main)
 Ignition switch: ON
 Release the accelerator pedal
 0.9 - 1.1 V
Depress the accelerator pedal fully
 4 V or more
19
 Accelerator pedal position sensor (sub)
 Ignition switch: ON
 Release the accelerator pedal
 0.4 - 0.6 V
Depress the accelerator pedal fully
 2 V or more
21
 Exhaust differential pressure sensor
 Engine: Idling after warming up
 0.4 - 0.7 V
Acceleration
 Voltage increases as engine speed increases.
22
 Air temperature sensor
 Ignition switch: ON
 When air temperature is 25°C
 Approximately 1.5 V
24
 Power source 2
 Ignition switch: "LOCK" (OFF)
 1 V or less
36
48
 Ignition switch: ON
 System voltage
25
 Fuel pump relay
 Ignition switch: ON
 System voltage
Engine: Idling
 1 V or less
26
 Starter relay
 Engine: Cranking
 0.2 - 2.0 V
Engine: Idling
 0.5 V or less
27
 Water in fuel sensor
 Ignition switch: ON
 3.7 V or more
29
 Air flow sensor
 Ignition switch: ON
 1.9 - 3.5 V
Engine: Idling after warming up
 2.8 - 5.3 V
31
 Ignition switch-ST
 Engine: Cranking
 8 V or more
32
 Power supply voltage applied to accelerator pedal position sensor (sub)
 Ignition switch: ON
 4.9 - 5.1 V
33
 Power supply voltage applied to exhaust differential pressure sensor
 Ignition switch: ON
 4.9 - 5.1 V
34
 Ignition switch-IG
 Ignition switch: ON
 System voltage
35
 Power source 1
 Ignition switch: "LOCK" (OFF)
 1 V or less
47
 Ignition switch: ON
 System voltage
38
 Radiator fan relay
 Radiator fan is not operating
 System voltage
Radiator fan is operating
 1 V or less
40
 Condenser fan relay
 Condenser fan is not operating
 System voltage
Condenser fan is operating
 1 V or less
41
 A/C compressor relay
  • Engine: Idling
  • A/C switch: OFF → ON (A/C compressor is operating)

 System voltage → 1 V or less
42
 Engine control relay 1
 Ignition switch: "LOCK" (OFF)
 System voltage
Ignition switch: ON
 1 V or less
45
 Fuel additive pump
 Fuel additive pump is not operating
 System voltage
Turn ignition switch ON after supplying fuel of 10L or more.
Voltage decreases when pulse is driven.
51
 Fuel flow regulator
 Engine: Idling after warming up → High load driving condition
 System voltage → Decreases
52
 EGR cooler solenoid valve
 Engine: Idling after warming up
 System voltage
54
 Engine oil level sensor
 Ignition switch: ON
 1 V or less
55
 Engine oil pressure switch
 Ignition switch: ON
 1 V or less
Engine: Idling
 System voltage
59
 Intake air pressure sensor
 Engine: Idling after warming up
 1.0 - 1.8 V
Acceleration
 Varies depending on the acceleration
63
 Power supply
 Ignition switch: "LOCK" (OFF)
 1 V or less
75
87
 Ignition switch: ON
 System voltage
64
 High pressure fuel regulator
 Engine: Idling after warming up
 System voltage
69
 Rail pressure sensor
 Engine: Idling after warming up
 Approximately 0.88 V
Acceleration
 Voltage slightly increases as engine speed increases.
70
 Throttle position sensor
 Engine: Idle speed and then stops
 1 V or less → temporarily 4.0 V or more → 1 V or less
76
 Power supply voltage applied to throttle position sensor
 Ignition switch: ON
 4.9 - 5.1 V
79
 Power supply voltage applied to intake air pressure sensor
 Ignition switch: ON
 4.9 - 5.1 V
80
 Power supply voltage applied to rail pressure sensor
 Ignition switch: ON
 4.9 - 5.1 V
83
 Engine oil temperature sensor
 Ignition switch: ON
 When engine oil temperature is 25 °C
 Approximately 2.8 V
88
 Power supply voltage applied to engine speed sensor
 Ignition switch: ON
 4.9 - 5.1 V
89
 Engine speed sensor
 Engine: Cranking
 1.0 - 6.0 V *1
Engine: Idling after warming up
 2.8 - 5.2 V *1
90
 Glow plug relay
 Ignition switch: ON (at engine coolant temperature of 5°C or less)
 4 V or more (1.5 - 18 seconds)
91
 Power supply voltage applied to camshaft position sensor
 Ignition switch: ON
 4.9 - 5.1 V
92
 Power supply voltage applied to EGR valve position sensor
 Ignition switch: ON
 4.9 - 5.1 V
93
 Engine coolant temperature sensor
 Ignition switch: ON
 When engine coolant temperature is 25 °C
 Approximately 2.8 V
98
 Camshaft position sensor
 Engine: Cranking
 1.0 - 6.0 V *1
Engine: Idling after warming up
 4.0 - 7.4 V *1
104
 Fuel temperature sensor
 Ignition switch: ON
 When fuel temperature is 25 °C
 Approximately 2.0 V
107
 Alternator FR terminal
 Engine: Idle operation after warm-up
Radiator fan: Non-operation
Head lamp switch: OFF → ON
Stop lamp: OFF → ON
Rear defogger switch: OFF → ON
 Voltage decreases
109
 Power supply voltage applied to variable geometry position sensor
 Ignition switch: ON
 4.9 - 5.1 V
110
 Alternator L terminal
 Ignition switch: ON
 1 V or less
111
 No. 1 fuel injector (high)
 Engine: Idling
 Approximately 12 V*1
Engine: 2,500 r/min
 Approximately 25 V*1
124
 No. 2 fuel injector (high)
 Engine: Idling
 Approximately 12 V*1
Engine: 2,500 r/min
 Approximately 25 V*1
123
 No. 3 fuel injector (high)
 Engine: Idling
 Approximately 12 V*1
Engine: 2,500 r/min
 Approximately 25 V*1
112
 No. 4 fuel injector (high)
 Engine: Idling
 Approximately 12 V*1
Engine: 2,500 r/min
 Approximately 25 V*1
135
 No. 1 fuel injector (low)
 Engine: Idling
 Approximately 8 V*1
Engine: 2,500 r/min
 Approximately 20 V*1
148
 No. 2 fuel injector (low)
 Engine: Idling
 Approximately 8 V*1
Engine: 2,500 r/min
 Approximately 20 V*1
147
 No. 3 fuel injector (low)
 Engine: Idling
 Approximately 8 V*1
Engine: 2,500 r/min
 Approximately 20 V*1
136
 No. 4 fuel injector (low)
 Engine: Idling
 Approximately 8 V*1
Engine: 2,500 r/min
 Approximately 20 V*1
117
 Variable geometry position sensor
 Engine: Idling after warming up
 Approximately 4.3 V *1
Acceleration
 Voltage decreases as engine speed increases.
118
 Intake air temperature sensor signal
 Ignition switch: ON
 When intake air temperature is 25 °C
 Approximately 3.3 V
120
 Swirl control solenoid valve
 Engine: Idling after warming up
 System voltage
122
 EGR valve motor
 Ignition switch: ON
 1 V or less
Engine: Idling after warming up
 0.5 ←→ 2.5 V*1 (Voltage varies slowly and repeatedly.)
142
 Throttle valve control motor
 Ignition switch: OFF → ON
 The voltage changes for a few seconds
133
 Variable geometry control motor (plus)
 Acceleration
 Voltage increases as engine speed increases.
146
 Proportional oxygen sensor heater
 Engine: Idling after warming up
 Approximately 8.8 V
Acceleration
 Voltage slightly decreases*1
note **1 : The shown voltage is the average value where an analog voltmeter is used (because a digital voltmeter may not be able to indicate the average voltage stably).

CHECK CHART FOR RESISTANCE AND CONTINUITY BETWEEN TERMINALS
1.Turn the ignition switch to "LOCK" (OFF) position.
2.Disconnect the engine-ECU connector.
3.Measure the resistance and check for continuity between the terminals of the engine-ECU harness-side connector while referring to the check chart.
note
  1. When measuring resistance and checking continuity, a harness for checking contact pin pressure should be used instead of inserting a test probe.
  2. 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-ECU and/or ohmmeter. Be careful to prevent this!
4. If the ohmmeter shows any deviation from the standard value, check the corresponding sensor, actuator and related electrical wiring, and the repair or replace.
5.After repair or replacement, recheck with the ohmmeter to confirm that the repair or replacement has corrected the problem.


Terminal No.
 Inspection item
 Normal condition
11 - Body earth
 ECU earth
 Continuity (2 Ω or less)
12 - Body earth
16 - 8
 Exhaust gas temperature sensor
 When exhaust gas temperature is 100 ± 10°C
 96,000 Ω
When exhaust gas temperature is 150 ± 10 °C
 96,000 Ω
When exhaust gas temperature is 200 ± 10 °C
 13,500 Ω
When exhaust gas temperature is 250 ± 10 °C
 6,300 Ω
When exhaust gas temperature is 300 ± 10 °C
 3,300 Ω
When exhaust gas temperature is 350 ± 10 °C
 1,850 Ω
When exhaust gas temperature is 400 ± 10 °C
 1,150 Ω
When exhaust gas temperature is 450 ± 10 °C
 755 Ω
When exhaust gas temperature is 500 ± 10 °C
 514 Ω
When exhaust gas temperature is 550 ± 10 °C
 362 Ω
When exhaust gas temperature is 600 ± 10 °C
 268 Ω
When exhaust gas temperature is 650 ± 10 °C
 198 Ω
When exhaust gas temperature is 700 ± 10 °C
 151 Ω
93 - 81
 Engine coolant temperature sensor
 Air temperature: -20 °C
 48.5 kΩ
Air temperature: 0 °C
 16.3 kΩ
Air temperature: 20 °C
 6.25 kΩ
Air temperature: 40 °C
 2.66 kΩ
Air temperature: 60 °C
 1.24 kΩ
Air temperature: 80 °C
 0.63 kΩ
Air temperature: 100 °C
 0.34 kΩ
104 - 105
 Fuel temperature sensor
 Fuel temperature: -20 °C
 22.4 - 29.4 kΩ
Fuel temperature: 0 °C
 7.35 - 9.25 kΩ
Fuel temperature: 20 °C
 2.74 - 3.32 kΩ
Fuel temperature: 40 °C
 1.14 - 1.34 kΩ
Fuel temperature: 60 °C
 0.52 - 0.60 kΩ
Fuel temperature: 80 °C
 0.26 - 0.29 kΩ
Fuel temperature: 100 °C
 0.14 - 0.15 kΩ
118 - 119
 Intake air temperature sensor
 Intake air temperature: 0 °C
 26.7 - 29.2 kΩ
Intake air temperature: 20 °C
 11.7 -12.6 kΩ
Intake air temperature: 40 °C
 5.61 - 5.94 kΩ