Page 538 of 1865
4B EEC SYSTEM
86U04A-139
86U04A-141
System Inspection
1. Check the vacuum hose routing.
2. If there is a poor connection, clog, or leak, repair
or replace as necessary.
3. Warm up the engine and run it at idle.
4. Disconnect vacuum hose A from No.
1
purge con-
trol valve and connect the SST to the hose.
86 U 04 A-140
5. Increase the engine speed to above 2,500 rpm
and verify that the gauge shows more than 150
mmHg (5.9 inHg).
6. If not correct, check the water thermo valve.
7. Reconnect hose A to No. 1 purge control valve.
8. Disconnect vacuum hose B from the canister and
place a finger over the end of the hose.
9. Accelerate the engine rapidly and check that vacu-
um is felt at above 1,500 rpm.
10. Reconnect hose B to the canister.
11. Disconnect vacuum hose C from the canister and
place a finger over the end of the hose.
12. Check that vacuum is felt.
13. If not correct, check the vacuum line between the
canister and the dynamic chamber for clogging.
86U04A-142
4B—76
Page 542 of 1865
4B PCV SYSTEM
POSITIVE CRANKCASE VENTILATION
(PCV)
SYSTEM
76G04B-106
The PCV valve is operated by the intake manifold vacuum.
When the engine is running at idle, the PCV valve is opened slightly and a small amount of blowby
gas is drawn into the dynamic chamber.
At high engine speeds, the PCV valve is further opened and a larger amount of blowby gas is drawn
into the dynamic chamber.
COMPONENT DESCRIPTION
Component Function
PCV valve Controls blowby gas amount pulled into engine
PCV VALVE
1. Warm up the engine to the normal operating tem-
perature and run it at idle.
2. Disconnect the PCV valve and the ventilation hose
from the cylinder head cover.
3. Close the PCV valve opening.
4. Check that vacuum is felt.
4B—80
Page 549 of 1865
CONTROL SYSTEM 4B
ENGINE CONTROL UNIT
Engine Signal Monitor (49 9200 162) and Adapter (49 9200 163).
Adapter harness 49 9200 163
Engine wiring harnessN
Selector switch
Monitor switch
Engine control unit
terminal number
Terminals
(A and 8)
ENGINE SIGNAL MONITOR
86U04A-171
The Engine Signal Monitor (49 9200 162) was developed to check the control unit terminal voltages.
This monitor easily inspects the individual terminal voltages through selection of the monitor switch.
How to Use the Engine Signal Monitor
1. Connect the Engine Signal Monitor (49 9200 162) between the engine control unit and the en-
gine harness using the adapter (49 9200 163).
2. Turn the selector switch and monitor switch to select the terminal number.
3. Check the terminal voltage.
Caution
Never apply voltage to terminals A and B.
4B-87
Page 550 of 1865
4B CONTROL SYSTEM
Terminal Voltage
If the input and output devices and related wiring are normal, but the engine control unit terminal volt-
age is incorrect, replace the engine control unit.
Terminal Input Output Connection to Voltage (After warming-up) Remarks Terminal Input Output Connection to IGN: ON Idle Remarks
1A — — — — —
1B o Self-Diagnosis Checker (Code number)
For 3sec. after ignition switch OFF ->• ON: below 6.2V (Buzzer sounds) After 3sec.: Battery voltage (Buzzer does not sound)
• Using Self-Diagnosis Check-er and test con-nector grounded • Buzzer sounds: below 6.2V • Buzzer does not sound: Battery voltage
1C — — — — —
1D o Self-Diagnosis Checker (Monitor lamp)
Test connector grounded
For 3sec. after igni-tion switch OFF ON:
below 6.2V (light il-luminates) After 3sec.: Battery voltage (light does not illuminate)
(Test connector grounded) approx. 10V (Test connector not grounded) Monitor lamp ON: below 6.2V Monitor lamp OFF: Battery voltage
With Self-Diagnosis
Checker
1E O Idle switch Accelerator pedal released: below 1.5V
Accelerator pedal depressed: Battery voltage
1F o A/C relay A/C switch ON: below 2.5V A/C switch OFF: Battery voltage
Blower motor ON
1G — — — — —
1H o Water thermo switch Below 1,5V Radiator temp.:
above 17°C (63°F)
11 o Electrical load con-trol unit Electrical load ON: below 1.5V Electrical load OFF: Battery voltage Electrical load: Rear defroster Headlight Blower motor (3rd & 4th position) Electrical fan
1J o Brake light switch Brake pedal released: below 1.5V
Brake pedal depressed: battery voltage
1K — — — — — —
1L o A/C switch A/C switch ON: below 1.5V
A/C switch OFF: battery voltage
Blower motor: ON
1M o Ignition coil © terminal Battery voltage *1 Battery voltage *1 Engine Signal Monitor: green and red lights flash
1N — — — — —
10 — — — —
4B-88
Page 554 of 1865
4B CONTROL SYSTEM
P/S pressure switch-^—^
86U04A-176
P/S PRESSURE SWITCH
Inspection
1. Disconnect the P/S pressure switch connector.
2. Connect an ohmmeter to the switch.
3. Start the engine. Check continuity of the switch
while turning the steering wheel at idle.
P/S Continuity
Turning Yes
Not turning No
4. Connect the switch connector after checking.
Note
Refer to section 10 for replacement of the P/S
pressure switch.
INHIBITOR SWITCH
Inspection
1. Disconnect the inhibitor switch connector.
2. Connect an ohmmeter to the switch.
3. Check continuity of the switch.
Position Continuity
P and N ranges Yes
Other ranges No
4. Connect the switch connector after checking.
Note
Refer to Section 7B for replacement of the in-
hibitor switch.
4B—92
Page 555 of 1865
4B CONTROL SYSTEM
E/L CONTROL UNIT
Inspection
1. Connect a voltmeter between the E/L control unit
and ground.
2. Start the engine and check the terminal voltages
as described below.
69G04A-174
Terminal Input Output Connection to Voltage (after warm-up) Remarks Terminal Input Output Connection to Ignition switch: ON idle Remarks
A
(BW) — — Ignition switch Battery voltage
B — — — — — —
C
(B) — — Ground OV
D (LY) 0 Electrical fan relay
Battery voltage Coolant temp.: below 97°C (207°F) D (LY) 0 Electrical fan relay
Below 1,5V Coolant temp.:
above 97°C (207°F)
E
(GY) o Engine control unit
(11)
OV E/L: ON E
(GY) o Engine control unit
(11) Battery voltage E/L: OFF
F (RB) 0 Headlight switch
Battery voltage Headlight switch:
ON F (RB) 0 Headlight switch
Below 1,5V Headlight switch:
OFF
G (LB) 0 Blower motor switch
Below 1,5V Blower motor switch: ON (3rd or 4th position) G (LB) 0 Blower motor switch
Approx. 5V Others
H
(BL) 0 Rear defroster switch
Below 1,5V Rear defroster switch: ON H
(BL) 0 Rear defroster switch Battery voltage Rear defroster switch: OFF
76G04B-131
Replacement
1. Remove the engine control unit. (Refer to page
4B-91)
2. Replace the E/L control unit.
3. Install in the reverse order of removal.
4B—93
Page 557 of 1865
CONTROL SYSTEM 4B
76G04B-114
c jr y—
D
'
CO CO
76G04B-115
76U04A-018
THROTTLE SENSOR
Inspection of Terminal Voltage
1. Remove the rubber boot from the connector.
2. Turn the ignition switch ON.
3. Check voltage between each terminal and a
ground.
4. Open the throttle valve and again check voltage
between each terminal and a ground.
Condition
Terminal Closed Fully open
A(Vt) 0.4—0.6V Approx. 4.0V
B (GND) Below 1.5 V
C (V ref) 4.5—5.5 V
D (IDL) Below 1.5 V Approx. 12 V
5. If not correct at the D terminal only, check the throt-
tle sensor setting.
6. If not correct on other terminals, check resistance
at the throttle sensor (Refer to page 4B—97) and
terminals (2A, 2C, 1E and 2G) (Refer to page
4B—88 and 89) of the engine control unit and wir-
ing harness.
7. Install the rubber boot on the connector.
Throttle Sensor Setting
Inspection
1. Disconnect the connector from the throttle sensor.
2. Connect the SST to the throttle sensor or connect
an ohmmeter between terminals B and D.
76G04B-116
4B-95
Page 560 of 1865
4B CONTROL SYSTEM
76G04B-121
86U04A-206
Check connector; Green (6 pin)y
49 H018 9A1
OXYGEN SENSOR
Inspection of Output Voltage
1. Warm up the engine and run it at idle.
2. Disconnect the oxygen sensor connector.
3. Connect a voltmeter between the oxygen sensor
and ground.
4. Run the engine at 4,000 rpm until the voltmeter
indicates approx. 0.55V.
5. Increase and decrease the engine speed suddenly
several times. Check to see that when the speed
is increased the meter reads between 0.5V—1.0V,
and when the speed is decreased it reads between
0V—0.4V
6. If the voltmeter doesn't indicate as specified, re-
place the oxygen sensor.
Inspection of Sensitivity
Caution
Do not ground the test connector (Green,
1-pin).
1. Warm up the engine to the normal operating tem-
perature and run it at idle.
2. Connect the SST to the check connector.
76G04B-133
Monitor lamp
SELF-DIAGNOSIS CHECKER
MONITOR > o .000 /TT\' o
SELECT SW «
86U04A-208
3. Increase the engine speed to between 2,000 and
3,000 rpm, and check that the monitor lamp flash-
es for 10 seconds.
Monitor lamp: Flashes ON and OFF
more than 8 times/10 sec
4B—98
