CHECK AT THE ECU TERMINALS



1.Disconnect the engine-ECU connectors, and connect check harness special tool MB992110 between the engine-ECU connectors.
2.Measure the voltage between each check harness connector terminal and check harness connector earth terminal GNDB or GNDE.
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.
Terminal code
Inspection Item
Check condition (Engine condition)
Normal condition
1
OCVI
Oil feeder control valve
Continuous idling mode
Release the accelerator pedal
System voltage
Excessive acceleration
Voltage decreases
2
INJ1
No. 1 injector
Engine: While continuous idling mode, suddenly depress the accelerator pedal
From 9 - 15 V*1, it is slightly reduced temporarily.
3
INJ2
No. 2 injector
18
INJ3
No. 3 injector
19
INJ4
No. 4 injector
4
CIL1
Ignition coil No. 1

  • Continuous idling mode
  • Engine: 3,000 r/min

0.3 - 3.0 V*1
5
CIL2
Ignition coil No. 2
20
CIL3
Ignition coil No. 3
21
CIL4
Ignition coil No. 4
8
SGT
Crank angle sensor
Continuous idling mode
2.0 - 3.0 V*1
9
5V
Sensor impressed voltage
Power supply mode of electric motor switch: ACC
System voltage
10
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.
  • Power supply mode of electric motor switch: ACC

Fully close the throttle valve with your finger
0.3 - 0.7 V
Fully open the throttle valve with your finger
4.4 - 4.8 V
11
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.
  • Power supply mode of electric motor switch: ACC

Fully close the throttle valve with your finger
4.3 - 4.7 V
Fully open the throttle valve with your finger
0.2 - 0.6 V
12
TPS5
Applied voltage to the throttle position sensor
Power supply mode of electric motor switch: ACC
4.9 - 5.1 V
14
CPI
Camshaft position sensor
Continuous idling mode
2.0 - 3.0 V*1
15
ETV+
Throttle valve control servo (+)
Power supply mode of electric motor switch: ACC → OFF
Decreases slightly from the auxiliary battery voltage
16
ETV-
Throttle valve control servo(-)
Power supply mode of electric motor switch: ACC → OFF
Decreases slightly from the auxiliary battery voltage
26
WTS
Engine coolant temperature sensor
Power supply mode of electric motor switch: ACC
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
31
EGRA
Exhaust gas recirculation valve (A)
Power supply mode of electric motor switch: OFF → ACC
To initialise, energise exhaust gas recirculation valve for three seconds and de-energise it
32
EGRB
Exhaust gas recirculation valve (B)
47
EGRC
Exhaust gas recirculation valve (C)
48
EGRD
Exhaust gas recirculation valve (D)
34
LHFL
Linear A/F sensor heater
Continuous idling mode
(1 minute after starting engine)
8 - 11 V*1
35
OHRL
Oxygen sensor (rear) heater
Continuous idling mode
(20 seconds after starting engine)
9 - 11 V*1
36
OPSW
Engine oil pressure switch
Power supply mode of electric motor switch: ACC
1 V or less
Continuous idling mode
System voltage
37
PURG
Purge control solenoid valve
Power supply mode of electric motor switch: ACC
System voltage
Continuous idling mode
Voltage decreases
40
O2RL
Oxygen sensor (rear)
Continuous idling mode
0.6 - 1.5 V
41
ORLE
Oxygen sensor (rear) offset voltage
Power supply mode of electric motor switch: ACC
0.4 - 0.6 V
44
MAP5
Applied voltage to the manifold absolute pressure sensor
Power supply mode of electric motor switch: ACC
4.9 - 5.1 V
45
MAP
Manifold absolute pressure sensor
Power supply mode of electric motor switch: ACC
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: After warm-up
  • Continuous idling mode

Release the accelerator pedal
0.6 - 1.4 V
Acceleration
Varies depending on acceleration
72
RSB
Power supply voltage applied to throttle valve control servo
Power supply mode of electric motor switch: ACC
System voltage
73
C/R
Engine control relay
Power supply mode of electric motor switch: OFF
System voltage
Power supply mode of electric motor switch: ACC
1 V or less
82
BAT1
Power supply
Power supply mode of electric motor switch: ACC
System voltage
84
C/RL
Throttle valve control servo relay
Power supply mode of electric motor switch: OFF
0 - 0.1 V
Power supply mode of electric motor switch: ACC
1 V or less
87
AFS
Air flow sensor

  • Continuous idling mode
  • Engine: Gradually increase the speed

Voltage increase in response to engine speed
89
ATS
Intake air temperature sensor
Power supply mode of electric motor switch: ACC
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 80°C
0.4 - 1.0 V
92
IGN
Ignition switch - IG
Power supply mode of electric motor switch: ACC
System voltage
96
FP/R
Fuel pump relay
Power supply mode of electric motor switch: ACC
System voltage
Continuous idling mode
1 V or less
97
ATS5
Applied voltage to the air flow sensor
Power supply mode of electric motor switch: ACC
4.9 - 5.1 V
104
BACK
Backup power supply
Power supply mode of electric motor switch: OFF
System voltage
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).

CHECK CHART FOR RESISTANCE AND CONTINUITY BETWEEN TERMINALS


1.Turn off the power supply mode of the electric motor switch.
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)
1 - 82
OCVI - BAT1
Oil feeder control valve
6.9 - 7.9 Ω (at 20°C)
15 - 16
ETV+ - ETV-
Throttle valve control servo
0.3 - 100 Ω (at 20°C)
26 - 27
WTS - WTSE
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)
31 - 82
EGRA - BAT1
Exhaust gas recirculation valve (A)
20 - 24 Ω (at 20°C)
32 - 82
EGRB - BAT1
Exhaust gas recirculation valve (B)
47 - 82
EGRC - BAT1
Exhaust gas recirculation valve (C)
48 - 82
EGRD - BAT1
Exhaust gas recirculation valve (D)
34 - 82
LHFL - BAT1
Linear A/F sensor heater
2.3 - 4.2 Ω (at 20°C)
35 - 82
OHRL - BAT1
Oxygen sensor (rear) heater
4.5 - 8.0 Ω (at 20°C)
37 - 82
PURG - BAT1
Purge control solenoid valve
22 - 26 Ω (at 20°C)
71 - body earth
RSG - body earth
ECU earth
Continuity (2 Ω or less)
81 - body earth
GNDB - body earth
83 - body earth
RSH - body earth
93 - body earth
GNDE - body earth
88 - 89
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 *: Values in square brackets are only advisory.