CHECK AT THE ECU TERMINALS


1.Disconnect the engine-ECU connectors A-34 and A-35, and connect check harness special tool MB991987 between the engine-ECU connectors.
2.Measure the voltage between each check harness connector terminal and check harness connector earth terminal (No. 75 or No. 76).
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 connectors 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 connectors 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
 Throttle valve control servo (+)
  • Ignition switch: "ON"
  • Accelerator pedal: fully opened → fully closed

 Decreased slightly (approximately 2 V) from battery voltage.
8
 No. 1 injector
 While engine is idling after having warmed up, suddenly depress the accelerator pedal.
 From 9 - 13 V*, momentarily drops slightly
9
 No. 2 injector
23
 No. 3 injector
24
 No. 4 injector
10
 Ignition coil - No. 1
 Engine: 3,000 r/min
 0.3 - 2.0 V*
25
 Ignition coil - No. 2
40
 Ignition coil - No. 3
55
 Ignition coil - No. 4
12
 Camshaft position sensor
 Engine: Cranking
 2.0 - 4.8 V*
Engine: Idling
 3.0 - 4.0 V*
13
 Crank angle sensor
 Engine: Cranking
 0.4 - 4.0 V*
Engine: Idling
 2.0 - 3.0 V*
14
 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
15
 Throttle position sensor (main)
  • Remove the intake air hose at the throttle body
  • Disconnect the electronic-controlled throttle valve connector, and then connect terminal numbers No. 1, No. 2, No. 3 and No. 4 with the use of the special tool (MB991658).
  • Ignition switch: "ON"

 Fully close the throttle valve with your finger
 0.4 - 0.6 V
Fully open the throttle valve with your finger
 4.35 - 4.65 V
16
 Throttle position sensor (sub)
  • Remove the intake air hose at the throttle body
  • Disconnect the electronic-controlled throttle valve connector, and then connect terminal numbers No. 1, No. 2, No. 3 and No. 4 with the use of the special tool (MB991658).
  • Ignition switch: "ON"

 Fully close the throttle valve with your finger
 4.4 - 4.6 V
Fully open the throttle valve with your finger
 0.35 - 0.65 V
22
 Throttle valve control servo (-)
  • Ignition switch: "ON"
  • Accelerator pedal: fully closed → fully opened

 Decreased slightly (approximately 2V) from battery voltage.
31
 Power supply voltage applied to throttle position sensor
 Ignition switch: "ON"
 4.9 - 5.1 V
38
 Purge control solenoid valve
 Ignition switch: "ON"
 System voltage
Engine: warming up within 3 minutes, 2,000 r/min or more
 Decreased voltage
50
 Oil pressure switch
 Ignition switch: "ON"
 0.5 V or less
Engine: Idling after warming up
 System voltage
51
 Alternator L terminal
 Ignition switch: "ON"
 0.5 - 2.0 V
Engine: Idling
 System voltage
52
 Oil control valve
 Ignition switch: "ON"
 System voltage
Under the high load operation
 4.0 - 10 V*
53
 Alternator G terminal
  • Engine: Warm, idle (cooling fan: OFF)
  • Headlamp: OFF → ON
  • Stop lamp: OFF → ON
  • Rear defogger switch: OFF → ON

 Increased voltage
54
 Alternator FR terminal
  • Engine: Warm, idle (cooling fan: OFF)
  • Headlamp: OFF → ON
  • Stop lamp: OFF → ON
  • Rear defogger switch: OFF → ON

 Decreased voltage
65
 Waste gate solenoid valve
 Ignition switch: "ON"
 System voltage
Engine: After warm-up, idle operation (When using premium gasoline)
 1 V or less
66
 Fuel pressure control solenoid valve
 Ignition switch: "ON"
 System voltage
Engine: Cranking → Idle operation (within approximately 2 minutes or less)
 1 V or less → System voltage
77
 Power supply
 Ignition switch: "ON"
 System voltage
92
78
 Power supply voltage applied to throttle valve control servo
 Ignition switch: "ON"
 System voltage
79
 Oxygen sensor heater (front)
  • Engine: Warm, Idle
  • After 1 minutes pass from when the engine starts

 1 V or less
Engine: 4,000 r/min
 System voltage
80
 Ignition switch - ST
 Engine: Cranking
 8 V or more
81
 Fuel pump relay
Ignition switch: ON
 System voltage
Engine: Idle speed
 1 V or less
82
 Backup power supply
 Ignition switch: "ON"
 System voltage
83
 Accelerator pedal position sensor (main)
 Ignition switch: "ON"
 Release the accelerator pedal
 0.95 - 1.05 V
Depress the accelerator pedal fully
 3.0 V or more
85
 Power supply voltage applied to accelerator pedal position sensor (main)
 Ignition switch: "ON"
 4.9 - 5.1 V
86
 Power supply voltage applied to accelerator pedal position sensor (sub)
 Ignition switch: "ON"
 2.4 - 2.6 V
88
 Accelerator pedal position sensor (sub)
 Ignition switch: "ON"
 Release the accelerator pedal
 0.45 - 0.55 V
Depress the accelerator pedal fully
 1.5 V or more
94
 Oxygen sensor heater (rear)
  • Engine: Warm, Idle
  • After 4 minutes pass from when the engine starts

 1 V or less
Engine: 5,000 r/min
 System voltage
95
 A/C compressor relay
  • Engine: Idling
  • A/C switch: OFF → ON (when the compressor is active)

 Battery voltage → 1 V or less
97
 Oxygen sensor (front)
 Engine: Running at 2,500 r/min after warmed up (Check using a digital type voltmeter)
 0 <=> 0.8 V (Changes repeatedly)
100
 Oxygen sensor (rear)
 Engine: Excessive acceleration after warmed up (Check using a digital type voltmeter)
 0 <=> 0.6 V (Changes repeatedly)
107
 Engine control relay
 Ignition switch: "LOCK" (OFF)
 System voltage
Ignition switch: "ON"
 1 V or less
113
 Clutch switch
 Ignition switch: "ON"
 Release the clutch pedal
 System voltage
Depress the clutch pedal fully
 0.5 V or less
122
 Ignition switch - IG
 Ignition switch: "ON"
 System voltage
123
 Throttle valve control servo relay
 Ignition switch: "LOCK" (OFF)
 0 - 0.1 V
Ignition switch: "ON"
 1 V or less
125
 Starter relay
 Ignition switch: "ON"
 System voltage
Engine: Cranking
 1 V or less
Engine: Idling
 System voltage
126
 Air flow sensor
 Engine: Gradually increase the speed
 Voltage increase in response to revving
129
 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
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 (Check condition)
7 - 22
 Throttle valve control servo
 0.3 - 100 Ω (at 20°C)
8 - 77
 No. 1 injector
 10.5 - 13.5 Ω (at 20°C)
9 - 77
 No. 2 injector
23 - 77
 No. 3 injector
24 - 77
 No. 4 injector
14 - 29
 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)
38 - 77
 Purge control solenoid valve
 30 - 34 Ω (at 20°C)
52 - 77
 Oil control valve
 6.9 - 7.9 Ω (20°C)
65 - 77
 Waste gate solenoid valve
 29 - 35 Ω (at 20°C)
66 - 77
 Fuel pressure control solenoid valve
 29 - 35 Ω (20°C)
75 - Body earth
 ECU earth
 Continuity (2 Ω or less)
76 - Body earth
93 - Body earth
108 - Body earth
77 - 79
 Oxygen sensor heater (front)
 5 - 30 Ω (at 20°C)
77 - 94
 Oxygen sensor heater (rear)
 5 - 30 Ω (at 20°C)
102 - 129
 Intake air temperature sensor
 13 - 17 kΩ (When intake air temperature is -20°C)
5.4 - 6.6 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)
0.31 - 0.43 kΩ (When intake air temperature is 80°C)