MPI –
Troubleshooting
13-63
ENGINE-ECU INSPECTION
TERMINAL VOLTAGES
Engine ECU connector
Terminal
No.
Check item
Check condition (Engine condition)
Normal condition
1
No.1 injector
While engine is idling after having been warmed up,
suddenly depress the accelerator pedal
Momentarily drops
slightly from 11
14 V
14
No.2 injector
suddenly depress the accelerator pedal.
slightly from 11 – 14 V.
2
No.3 injector
15
No.4 injector
3
Fuel pressure control
valve
Ignition switch: ON
System voltage
valve
Engine: Cranking to idling (within about two minutes)
0 – 3 V to sytem
voltage
4
Stepper motor coil (A1)
Engine: Immediately after engine has been started
for warming up
Changes repeatedly
from system voltage
17
Stepper motor coil (A2)
for warming up
from system voltage
to 0 – 6 V and from 0
6 V to system
5
Stepper motor coil (B1)
– 6 V to system
voltage.
18
Stepper motor coil (B2)
6
Secondary air control
solenoid valve
Ignition switch: ON
System voltage
8
Fuel pump relay
Ignition switch: ON
System voltage
Engine: Idling
0 – 3 V
10
Power transistor unit
(A)
Engine speed: 3,000 r/min
0.3 – 3.0 V
23
Power transistor unit
(B)
11
Wastegate solenoid
valve
Ignition switch: ON
System voltage
valve
Engine: At idle after having been warmed up (when
premium gasoline is used)
0 – 3 V
12
Power supply
Ignition switch: ON
System voltage
25
19
Air flow sensor reset
signal
Engine: Idling
0 – 1 V
signal
Engine speed: 3,000 r/min
6 – 9 V
20
Fan motor relay (HI)
<EVOLUTION-IV, V>
Fan not operating (coolant temperature: 90
_
C or
below)
System voltage
Fan at high speed (coolant temperature: 105
_
C or
above)
0 – 3 V