CHECK AT THE ECU TERMINALS



 1.Connect a needle-nosed wire probe to a voltmeter probe.
2.Insert the needle-nosed wire probe into each of the engine-ECU connector terminals from the wire side, and measure the voltage while referring to the check chart.
note
  1. Make the voltage measurement with the engine-ECU connector connected.
  2. You may find it convenient to pull out the engine-ECU to make it easier to reach the connector terminals.
  3. 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!
3.If voltmeter shows any division from standard value, check the corresponding sensor, actuator and related electrical wiring, then repair or replace.
4.After repair or replacement, recheck with the voltmeter to confirm that the repair has corrected the problem.

TERMINAL VOLTAGE CHECK CHART




Terminal No.
 Terminal code
 Inspection Item
 Check condition (Engine condition)
 Normal condition
1
 INJ1
 No. 1 injector
 Engine: While engine is idling after having warmed up, suddenly depress the accelerator pedal.
 From 9 - 14 V*1, it is slightly reduced temporarily.
2
 INJ4
 No. 4 injector
3
 OHFL
 Left bank oxygen sensor (front) heater
 Engine: Idling operation after warm-up (after 15 seconds has elapsed)
 9 - 11 V*1
Under the high load operation
9 - 11 V*1 → System voltage
4
 OHFR
 Right bank oxygen sensor (front) heater
 Engine: Idling operation after warm-up (after 15 seconds has elapsed)
 9 - 11 V*1
Under the high load operation
 9 - 11 V*1 → System voltage
5
 PURG
 Purge control solenoid valve
 Ignition switch: ON
 System voltage
Engine: 2,500 r/min after warm-up (with 4 minutes after the engine starting sequence is completed)
 Voltage decreases
7
 CIL1
 Ignition coil No. 1
 Engine: 3,000 r/min
 0.3 - 3.0 V*1
8
 CIL4
 Ignition coil No. 4
9
 INJ2
 No. 2 injector
 Engine: While engine is idling after having warmed up, suddenly depress the accelerator pedal.
 From 9 - 14 V*1, it is slightly reduced temporarily.
10
 INJ5
 No. 5 injector
12
 OHRL
 Left bank oxygen sensor (rear) heater
 Engine: Idling operation after warm-up (after 15 seconds has elapsed)
 1.0 V or less
Under the high load operation
 System voltage
13
 OHRR
 Right bank oxygen sensor (rear) heater
 Engine: Idling operation after warm-up (after 15 seconds has elapsed)
 1.0 V or less
Under the high load operation
 System voltage
14
 EGRA
 Exhaust gas recirculation valve (A)
 Ignition switch: OFF → ON
 To initialise, energise exhaust gas recirculation valve for three seconds and de-energise it
15
 EGRC
 Exhaust gas recirculation valve (C)
17
 TPSM
 Throttle position sensor (main)
  • Remove the intake air hose at the throttle body.
  • Disconnect the connector of the electronic-controlled throttle valve.
  • With the special tool test harness (MB991658) bridge only the mating terminals of No. 3, No. 4, No. 5, and No. 6 of the disconnected connectors.
  • Ignition switch: ON (engine stopped)

 Fully close the throttle valve with your finger.
 0.3 - 0.7 V
Fully open the throttle valve with your finger.
 4.0 V or more
18
 TPS5
 Power supply voltage applied to throttle position sensor
 Ignition switch: ON
 4.9 - 5.1 V
19
 OPSW
 Engine oil pressure switch
 Ignition switch: ON
 1.0 V or less
Engine: Idle operation
 System voltage
20
 ALTL
 Alternator L terminal
 Ignition switch: ON
 0.5 - 2.0 V
Engine: Idle operation
 System voltage
21
 ALTF
 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
22
 CIL2
 Ignition coil No. 2
 Engine: 3,000 r/min
 0.3 - 3.0 V*1
23
 CIL5
 Ignition coil No. 5
24
 INJ3
 No. 3 injector
 Engine: While engine is idling after having warmed up, suddenly depress the accelerator pedal.
 From 9 - 14 V*1, it is slightly reduced temporarily.
25
 INJ6
 No. 6 injector
26
 OCV
 Oil feeder control valve
 Engine: Idling operation after warm-up
 System voltage
Engine: 5,000 r/min
 1 V or less → 4.0 - 10 V*1(After a few seconds pass)
28
 EGRB
 Exhaust gas recirculation valve (B)
 Ignition switch: OFF → ON
 To initialise, energise exhaust gas recirculation valve for three seconds and de-energise it
29
 EGRD
 Exhaust gas recirculation valve (D)
30
 TPSS
 Throttle position sensor (sub)
  • Remove the intake air hose at the throttle body.
  • Disconnect the connector of the electronic-controlled throttle valve.
  • With the special tool test harness (MB991658) bridge only the mating terminals of No. 3, No. 4, No. 5, and No. 6 of the disconnected connectors.
  • Ignition switch: ON (engine stopped)

 Fully close the throttle valve with your finger.
 4.3 V - 4.7 V
Fully open the throttle valve with your finger.
 1.0 V or less
32
 P/S
 Power steering fluid pressure switch
 Engine: Idle operation after warm-up
 Steering wheel: stationary
 System voltage
Steering wheel: turning
 1 V or less
33
 ALTG
 Alternator G 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 rises
34
 CIL3
 Ignition coil No. 3
 Engine: 3,000 r/min
 0.3 - 3.0 V*1
35
 CIL6
 Ignition coil No. 6
41
 ETV+
 Throttle valve control servo (+)
  • Ignition switch: ON
  • Accelerator pedal: fully opened → fully closed

 Decreases slightly (Approximately 2 V) from the battery voltage
42
 ETV-
 Throttle valve control servo (-)
  • Ignition switch: ON
  • Accelerator pedal: fully closed → fully opened

 Decreases slightly (Approximately 2 V) from the battery voltage
44
 O2VE
 Oxygen sensor offset voltage
 Ignition switch: ON
 0.4 - 0.6 V
45
 O2FL
 Left bank oxygen sensor (front) offset voltage
 Engine: Maintain 2,500 r/min after warm-up
 0.5 <=> 1.4 V (repeat the alteration)
46
 O2FR
 Right bank oxygen sensor (front)
47
 RSB
 Power supply voltage applied to throttle valve control servo
 Ignition switch: ON
 System voltage
49
 WTS
 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
50
 ATS
 Intake air temperature sensor
 Ignition switch: ON
 When the intake air temperature is -20°C
 3.8 - 4.4 V
When the intake air temperature is 0°C
 3.2 - 3.8 V
When the intake air temperature is 20°C
 2.3 - 2.9 V
When the intake air temperature is 40°C
 1.5 - 2.1 V
When the intake air temperature is 60°C
 0.8 - 1.4 V
When the intake air temperature is 80°C
 0.4 - 1.0 V
51
 5V
 Sensor supplied voltage
 Ignition switch: ON
 System voltage
55
 O2RL
 Left bank oxygen sensor (rear)
  • Transmission: 2nd
  • The engine speed is maintained to 3,500 r/min or more during an accelerated driving with the throttle full-open

 1.0 - 1.5 V
56
 O2RR
 Right bank oxygen sensor (front)
59
 C/RL
 Throttle valve control servo relay
 Ignition switch: ON → LOCK (OFF)
 1.0 V or less → System voltage → 1.0 V or less
61
 MAP
 Manifold absolute pressure sensor
 Ignition switch: ON
 At 0 m altitude
 3.8 - 4.2 V
At 600 m altitude
 3.5 - 3.9 V
At 1,200 m altitude
 3.3 - 3.7 V
At 1,800 m altitude
 3.0 - 3.4 V
Engine: Idle operation after warm-up
 0.6 - 1.4 V
Engine: While the engine is idling after warm-up, quickly depress the accelerator pedal
 Varies depending on the negative pressure at the inlet manifold
65
 SGC
 Camshaft position sensor
 Engine: Cranking
 0.4 - 4.0 V*1
Engine: Idle operation
 2.5 - 3.9 V*1
66
 SGT
 Crank angle sensor
 Engine: Cranking
 0.4 - 4.0 V*1
Engine: Idle operation
 2.0 - 3.0 V*1
72
 FP/R
 Fuel pump relay
 Ignition switch: ON
 System voltage
Engine: Idle operation
 1.0 V or less
77
 BACK
 Backup power supply
 Ignition switch: LOCK (OFF)
 System voltage
80
 AFS
 Air flow sensor
 Engine: Gradually increase the speed
 Voltage increase in response to revving
82
 AC/T
 Fin thermo sensor
 Evaporator surface temperature: 25°C (1.5 kΩ)
 1.1 - 1.3 V
88
 AC/S
 A/C switch
 Engine: Idling after warming up
 A/C switch: OFF
 System voltage
A/C switch: ON (A/C compressor is operating)
 0 - 3 V
89
 IGN
 Ignition switch - IG
 Ignition switch: ON
 System voltage
91
 AFS5
 Air flow sensor reference voltage
 Ignition switch: ON
 4.9 - 5.1 V
97
 ST
 Ignition switch - ST
 Engine: Cranking
 8 V or more
98
 STCD
 Starter active signal
 Engine: Cranking
 System voltage
Engine: Idling
 1.0 V or less
103
 STRL
 Starter relay
 Engine: Cranking
 System voltage
Engine: Idle operation
 1.0 V or less
104
 AC/R
 A/C compressor relay
  • Engine: Idle operation
  • A/C switch: OFF → ON
    (when the compressor is active)

 System voltage → 1.0 V or less
106
 BAT1
 Power supply
 Ignition switch: ON
 System voltage
108
 F/LO
 A/C condenser fan relay
 A/C condenser fan inactive state
 System voltage
A/C condenser fan rotation state
 1 V or less
110
 C/R
 Engine control relay
 Ignition switch: LOCK (OFF)
 System voltage
Ignition switch: ON
 1.0 V or less
111
 APSM
 Accelerator pedal position sensor (main)
 Ignition switch: ON
 Release the accelerator pedal
 System voltage
Depress the accelerator pedal fully
 4.4 V or more
112
 APS5
 Power supply voltage applied to accelerator pedal position sensor (main)
 Ignition switch: ON
 4.9 - 5.1 V
123
 APSS
 Accelerator pedal position sensor (sub)
 Ignition switch: ON
 Release the accelerator pedal.
 System voltage
Depress the accelerator pedal fully
 2.1 V or more
124
 AP5
 Power supply voltage applied to accelerator pedal position sensor (sub)
 Ignition switch: ON
 4.9 - 5.1 V
note *1: The shown voltage is the average value where an analogue voltmeter is used (because a digital voltmeter may not be able to indicate the average voltage stably).
note *2: If the battery is fully charged, the output reading may be incorrect.

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.
 Terminal code
 Inspection Item
 Standard value, normal condition (Check condition)
26 - 106
 OCV - BAT1
 Oil feeder control valve
 6.9 - 7.9 Ω (at 20°C)
41 - 42
 ETV+ - ETV-
 Throttle valve control servo
 0.3 - 80 Ω (at 20°C)
49 - 60
 WTS - E
 Engine coolant temperature sensor
 14 - 17 kΩ (at -20°C)
[5.1 - 6.5 kΩ (at 0°C)]*
2.1 - 2.7 kΩ (at 20°C)
[0.9 - 1.3 kΩ (at 40°C)]*
[0.48 - 0.68 kΩ (at 60°C)]*
[0.26 - 0.36 kΩ (at 80°C)]*
14 - 106
 EGRA - BAT1
 Exhaust gas recirculation valve (A)
 20 - 24 Ω (at 20°C)
28 - 106
 EGRB - BAT1
 Exhaust gas recirculation valve (B)
15 - 106
 EGRC - BAT1
 Exhaust gas recirculation valve (C)
29 - 106
 EGRD - BAT1
 Exhaust gas recirculation valve (D)
4 - 106
 OHFR - BAT1
 Right bank oxygen sensor (front) heater
 4.5 - 8.0 Ω (at 20°C)
3 - 106
 OHFL - BAT1
 Left bank oxygen sensor (front) heater
 4.5 - 8.0 Ω (at 20°C)
12 - 106
 OHRL - BAT1
 Left bank oxygen sensor (rear) heater
 7.0 - 12.0 Ω (at 20°C)
5 - 106
 PURG - BAT1
 Purge control solenoid valve
 22 - 26 Ω (at 20°C)
13 - 106
 OHRR - BAT1
 Right bank oxygen sensor (rear) heater
 7.0 - 12.0 Ω (at 20°C)
48 - body earth
 RSG - body earth
 ECU earth
 Continuity (2 Ω or less)
119 - body earth
 GNDB - body earth
120 - body earth
 GNDE - body earth
113 - 50
 AFSE - ATS
 Intake air temperature sensor
 13 - 18 kΩ (at -20°C)
5.3 - 6.7 kΩ (at 0°C)
2.3 - 3.0 kΩ (at 20°C)
0.30 - 0.45 kΩ (at 80°C)
note *: The value in square brackets is only advisory.