CHECK AT THE ECU TERMINALS


1.Disconnect the engine-ECU connectors B-05 and B-06, and connect check harness special tool MB992044 between the engine-ECU connectors.
2.Measure the voltage between each check harness connector terminal and check harness connector earth terminal (No. 64 or No. 65 or No. 66).
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
1
 No. 1 cylinder injector
 Engine: Idling after warming up
 Approximately 0.5 V*
2
 No. 2 cylinder injector
 Engine: Idling after warming up
 Approximately 0.5 V*
3
 No. 3 cylinder injector
 Engine: Idling after warming up
 Approximately 0.5 V*
46
 No. 4 cylinder injector
 Engine: Idling after warming up
 Approximately 0.5 V*
7
 Engine coolant temperature sensor
 Ignition switch: ON
 at approximately 90°C
 Approximately 0.4 V
8
 Engine coolant temperature sensor earth
 Ignition switch: ON
 0 - 0.2 V
12
 Crank angle sensor earth
 Ignition switch: ON
 0 - 0.2 V
13
 Crank angle sensor
 Engine: Cranking
 0.4 - 4.0 V
Engine: Idling
 2.0 - 3.0 V*
15
 Intake air control flap
 Engine: Idling after warming up
 1 V or less
Engine: Idling → Stopping (Ignition switch: OFF)
 8 V or more* (After a few seconds)
16
 Injector supply voltage
 Ignition switch: ON
 1.8 - 2.8 V
17
 Engine: Idling
 Approximately 0.6 V*
27
 Crank angle sensor supply voltage
 Ignition switch: ON
 4.9 - 5.1 V
40
 Intake air control flap diagnostic signal
 Ignition switch: ON
 System voltage
Engine: Idling after warming up
 System voltage
42
 Camshaft position sensor supply voltage
 Ignition switch: ON
 4.9 - 5.1 V
43
 Camshaft position sensor
 Engine: Cranking
 0.4 - 4.5 V
Engine: Idling
 3.0 - 4.0 V*
44
 Variable geometry solenoid valve
 Engine: Idling after warming up
 2.0 - 10 V*
Engine: 2,500 r/m
 4.0 - 12 V*
57
 Camshaft position sensor earth
 Ignition switch: ON
 0 - 0.2 V
60
 EGR cooler solenoid valve
 Ignition switch: ON
 System voltage

  • Engine: Idling
  • Engine coolant temperature: Lower than 30°C

 1 V or less

  • Engine: Idling
  • Engine coolant temperature: Higher than 45°C

 System voltage
61
 Power supply
 Ignition switch: OFF
 0 - 0.2 V (After approximately 10 seconds)
62
63
 Ignition switch: ON
 System voltage
64
 Engine-ECU earth
 Ignition switch: ON
 0 - 0.2 V
65
66
70
 Boost pressure sensor earth
 Ignition switch: ON
 0 - 0.2 V
72
 Boost pressure sensor
 Ignition switch: ON
 Altitude: 0 m
 Approximately 1.6 V
Engine: Racing
 Voltage increases
76
 Air flow sensor
 Ignition switch: ON
 0.2 - 1.8 V
Engine: Idling after warning up
 1.1 - 2.8 V
77
 Accelerator pedal position sensor (main)
 Ignition switch: ON
 Release the accelerator pedal
 0.9 - 1.1 V
Depres the accelerator pedal fully
 4.0 V or more
78
 Accelerator pedal position sensor (main) supply voltage
 Ignition switch: ON
 4.9 - 5.1 V
80
 Ignition switch-ST
 Engine: Cranking
 8 V or more
81
 Stop lamp switch
 Depress the brake pedal
 8 V or more
Release the brake pedal
 1 V or less
85
 A/C compressor relay
  • Engine: Idling
  • A/C switch: OFF → ON (A/C compressor is operating)

 System voltage → 1 V or less
86
 Starter relay
 Ignition switch: ON
 System voltage
Engine: Cranking
 1 V or less
Engine: Idling
 System voltage
90
 Fuel pump relay
 Ignition switch: ON
 System voltage
Engine: Cranking
 1 V or less
Engine: Idling
 1 V or less
98
 Air flow sensor earth
 Ignition switch: ON
 0 - 0.2 V
99
 Accelerator pedal position sensor (sub)
 Ignition switch: ON
 Release the accelerator pedal
 0.5 - 0.9 V
Depress the accelerator pedal fully
 3.5 V or more
100
 Accelerator pedal position sensor (sub) supply voltage
 Ignition switch: ON
 4.9 - 5.1 V
101
 Glow diagnostic signal
 Ignition switch: ON
 6 V or more
102
 Alternator FR terminal
  • Engine: Idling after warning up
  • Radiator fan: Not operating
  • Headlamp: OFF → ON
  • Stop lamp: OFF → ON
  • Rear defogger: OFF → ON

 Voltage decreases
112
 Glow control signal
 Ignition switch: ON
 1 - System voltage
120
 Intake air temperature sensor
 Ignition switch: ON
 at approximately 25°C
 1.5 -2.5 V
121
 Accelerator pedal position sensor (main) earth
 Ignition switch: ON
 0 - 0.2 V
122
 Air flow sensor supply voltage
 Ignition switch: ON
 4.9 - 5.1 V
131
 Engine control relay
 Ignition switch: OFF
 System voltage
Ignition switch: ON
 1 V or less
139
 Exhaust Gas Recirculation control solenoid valve
 Ignition switch: ON
 System voltage
Engine: Idling after warming up
 Approximately 5.5 V*
Engine: 3,000 r/min
 Approximately 8V*
140
 Engine oil pressure switch
 Ignition switch: ON
 System voltage
Engine: Idling
 0- 1 V (After a few seconds)
143
 Accelerator pedal position sensor (sub) earth
 Ignition switch: ON
 0 - 0.2 V
144
 Ignition switch-IG
 Ignition switch: OFF
 0 - 0.2 V
Ignition switch: ON
 System voltage
145
 Clutch switch
 Depress the clutch pedal
 0 - 3 V
Release the clutch pedal
 System voltage
152
 Alternator starting voltage
 Ignition switch: ON
 1 V or less
153
 Engine: Idling
 System voltage
note * :The average voltage is shown when an analog voltmeter is used (because the average voltage might not be shown stably when digital voltmeter is used).

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
1 - 16
 No. 1 cylinder injector
 Approximately 0.5 Ω (at 25°C)
2 - 16
 No. 2 cylinder injector
 Approximately 0.5 Ω (at 25°C)
3 - 16
 No. 3 cylinder injector
 Approximately 0.5 Ω (at 25°C)
16 - 46
 No. 4 cylinder injector
 Approximately 0.5 Ω (at 25°C)
7 - 8
 Engine coolant temperature sensor
 Approximately 1.1 kΩ (at 25°C)
24 - 25
 Fuel temperature sensor
 Approximately 0.78 kΩ (at 25°C)
44 - 61
 Variable geometry solenoid valve
 Approximately 17 Ω (at 25°C)
60 - 61
 EGR cooler solenoid valve
 Approximately 30 Ω (at 25°C)
61 - 139
 EGR control solenoid valve
 Approximately 16 Ω (at 25°C)
64 - Body earth
 Engine-ECU earth
 Continuity (1 Ω or less)
65 - Body earth
66- Body earth
70 - 120
 Intake air temperature sensor
 Approximately 1.1 kΩ (at 25°C)