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 chart procedures do not have the particular order.
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
Inlet oil feeder control valve
Ignition switch: "ON"
System voltage
Under the high load operation.
4 - 10 V*1
2
INJ1
No. 1 injector
Engine: While engine is idling after having warmed up, 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
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
6
NTSW
Starter active signal
Engine: Cranking
System voltage
Engine: Idling
1 V or less
8
SGT
Crank angle sensor
Engine: Cranking
0.4 - 4.0 V*1
Engine: Idle operation
2.0 - 3.0 V*1
9
5V
Sensor impressed voltage
Ignition switch: "ON"
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.
  • 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 - 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.
  • Ignition switch: "ON" (engine stopped)

Fully close the throttle valve with your finger.
4 V or more
Fully open the throttle valve with your finger.
1 V or less
12
TPS5
Applied voltage to the throttle position sensor
Ignition switch: "ON"
4.9 - 5.1 V
14
CPI
Inlet camshaft position sensor
Engine: Cranking
2.0 - 4.8 V*1
Engine: Idle operation
2.0 - 3.0 V*1
15
ETV+
Throttle valve control servo (+)

  • Ignition switch: "ON"
  • Accelerator pedal: fully closed → fully opened

Decreases slightly from the battery voltage
16
ETV-
Throttle valve control servo (-)

  • Ignition switch: "ON"
  • Accelerator pedal: fully closed → fully opened

Decreases slightly from the battery voltage
26
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
34
OHFL
Oxygen sensor (front) heater
Engine: Idle operation after warm-up
(20 seconds after starting engine)
9 - 11 V*1
Engine: Racing
System voltage
35
OHRL
Oxygen sensor (rear) heater
Engine: Idle operation after warm-up
(20 seconds after starting engine)
9 - 11 V*1
Engine: Racing
System voltage
36
OPSW
Engine oil pressure switch
Ignition switch: "ON"
1 V or less
Engine: Idle operation
System voltage
37
PURG
Purge control solenoid valve
Ignition switch: "ON"
System voltage
Engine: 3,000 r/min after warm-up (with 4 minutes after the engine starting sequence is completed)
Voltage decreases
38
O2FL
Oxygen sensor (front)
Engine: Maintain 2,500 r/min after warm-up
0.6 <=> 1.0 V (repeat the alteration)
39
OFLE
Oxygen sensor (front) offset voltage
Ignition switch: "ON"
0.4 - 0.6 V
40
O2RL
Oxygen sensor (rear)

  • Transmission: Ds range
  • 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
41
ORLE
Oxygen sensor (rear) offset voltage
Ignition switch: "ON"
0.4 - 0.6 V
44
MAP5
Applied voltage to the manifold absolute pressure sensor
Ignition switch: "ON"
4.9 - 5.1 V
45
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
60
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
61
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
62
ALTL
Alternator L terminal
Ignition switch: "ON"
0.5 - 2.0 V
Engine: Idle operation
System voltage
72
RBB
Power supply voltage applied to throttle valve control servo
Ignition switch: "ON"
System voltage
73
C/R
Engine control relay
Ignition switch: "LOCK" (OFF)
System voltage
Ignition switch: "ON"
1 V or less
74
APSM
Accelerator pedal position sensor (main)
Ignition switch: "ON"
Release the accelerator pedal
0.9 - 1.1 V
Depress the accelerator pedal fully
4.0 - 4.8 V
75
APS5
Applied voltage to the accelerator pedal position sensor (main)
Ignition switch: "ON"
4.9 - 5.1 V
77
APSS
Accelerator pedal position sensor (sub)
Ignition switch: "ON"
Release the accelerator pedal.
0.4 - 0.6 V
Depress the accelerator pedal fully
2.0 - 2.5 V
78
5VV
Applied voltage to the accelerator pedal position sensor (sub)
Ignition switch: "ON"
4.9 - 5.1 V
82
BAT1
Power supply
Ignition switch: "ON"
System voltage
84
C/RL
Throttle valve control servo relay
Ignition switch: "LOCK" (OFF)
0 - 0.1 V
Ignition switch: "ON"
1 V or less
87
AFS
Air flow sensor
Engine: Gradually increase the speed
Voltage increase in response to revving
89
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 80°C
0.4 - 1.0 V
92
IGN
Ignition switch - IG
Ignition switch: "ON"
System voltage
96
FP/R
Fuel pump relay
Ignition switch: "ON"
System voltage
Engine: Idle operation
1 V or less
97
AFS5
Applied voltage to the air flow sensor
Ignition switch: "ON"
4.9 - 5.1 V
102
AC/R
A/C compressor relay

  • Engine: Idle operation
  • A/C switch: "OFF" → "ON"
    (when the compressor is active)

System voltage → 1 V or less.
104
BACK
Backup power supply
Ignition switch: "LOCK" (OFF)
System voltage
105
ST
Ignition switch - ST
Engine: Cranking
System voltage
106
STRL
Starter relay
Engine: Cranking
System voltage
Engine: Idle operation
1 V or less
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)
1 - 82
DCV1 - BAT1
Inlet oil feeder control valve
6.9 - 7.9 Ω (at 20°C)
15 - 16
ETV+ - ETV-
Throttle valve control servo
0.3 - 80 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)
34 - 82
OHFL - BAT1
Oxygen sensor (front) heater
4.5 - 8.0 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)