Page 1137 of 2389
INSPECTION OF CIRCUIT OPENING
RELAY
1. INSPECT RELAY CONTINUITY
(a) Using an ohmmeter, check that there is continuity
between terminals STA and E1.
(b) Check that there is continuity between terminals B
and FC.
(c) Check that there is no continuity between terminals B
and FP.
If continuity is not as specified, replace the relay.
2. INSPECT RELAY OPERATION
(a) Apply battery voltage across terminals STA and E1.
(b) Using an ohmmeter, check that there is continuity between
terminals B and FP.
(c) Apply battery voltage across terminals B and FC.
(d) Check that there is continuity between terminals B
and FP.
If operation is not as specified, replace the relay.
Circuit Opening Relay
± EFI SYSTEMElectronic Control System (Circuit Opening Relay)FI±123
Page 1138 of 2389
3S±FE STA ± STJ
20 ± 40 below 30°C (86°F)
40 ± 60 above 40°C (I04°F)
STA ± Ground
20 ± 80
2VZ±FE STA ± STJ
25 ± 45 below 15°C (59°F)
65 ± 85 above 30°C (86°F)
STA ± Ground
25 ± 85
If the resistance is not as specified, replace the switch.
INSPECTION OF COLD START INJECTOR
TIME SWITCH
INSPECT RESISTANCE OF COLD START INJECTOR TIME
SWITCH
Using an ohmmeter, measure the resistance between each ter-
minal.
Resistance:
Cold Start Injector Time Switch
± EFI SYSTEMElectronic Control System (Cold Start Injector Time Switch)FI±124
Page 1139 of 2389
INSPECTION OF WATER TEMPERATURE
SENSOR
INSPECT RESISTANCE OF WATER TEMPERATURE
SENSOR
Using an ohmmeter, measure the resistance between the
terminals.
Resistance: Refer to chart
If the resistance is not as specified, replace the sensor.
Water Temperature Sensor
± EFI SYSTEMElectronic Control System (Water Temperature Sensor)FI±125
Page 1140 of 2389
INSPECTION OF EGR GAS TEMPERATURE
SENSOR
INSPECT EGR GAS TEMPERATURE SENSOR
Using an ohmmeter, measure the resistance between the terminals.
Resistance:
69.40 ± 88.50 k at 50° C (11210 F)
11.89 ±14.37 k at 100° C (212° F)
2.79 ± 3.59 k at 150° C (302° F)
If the resistance is not as specified, replace the sensor.
EGR Gas Temperature Sensor
(CALIF. only)
± EFI SYSTEMElectronic Control System (EGR Gas Temperature Sensor
(CALIF. only)FI±126
Page 1141 of 2389
3. INSPECT FUEL PRESSURE VSV
A. Inspect VSV for open circuit.
Using an ohmmeter, check that there is continuity between
terminals.
Resistance (Cold): 33 ± 39
If there is no continuity, replace the VSV.
INSPECTION OF FUEL PRESSURE
CONTROL SYSTEM.
1. INSPECT WATER TEMPERATURE SENSOR
(See page FI±49)
2. INSPECT INTAKE AIR TEMPERATURE SENSOR
(See page FI±37)
B. Inspect VSV for ground.
Using an ohmmeter, check that there is no continuity be-
tween each terminal and body.
If there is continuity, replace the VSV.
Fuel Pressure Control System
± EFI SYSTEMElectronic Control System (Fuel Pressure Control System)FI±127
Page 1142 of 2389
(b) Apply battery voltage across the terminals
(c) Check that air flows from pipe E to filter.
If operation is not as specified, replace the VSV. C. Inspect VSV operation
(a) Check that air flow from pipes E to G.
± EFI SYSTEMElectronic Control System (Fuel Pressure Control System))FI±128
Page 1143 of 2389

Main Oxygen Sensor
INSPECTION OF OXYGEN SENSOR
1. WARM UP ENGINE
Allow the engine to warm up to normal operating temperature.
2. INSPECT FEEDBACK VOLTAGE
Connect the positive (+) probe of a voltmeter to terminal VF1
of the check connector, and negative (±) probe to terminal
E1. Perform the test as follows:
Warm up the oxygen sensor with the engine at 2,500
rpm for approx. 90 seconds. And maintain engine at
2,500 rpm.
Normal code, code Nos. Malfunction code(s)
21, 25 and 26 (Ex. code Nos. 21, 25 and 26y Warm up the oxygen sensor with the engine at 2,500
rpm for approx. 90 seconds.
Disconnect terminals TE1 and E1 of the check connector.
And maintain engine speed at 2,500 rpm.Connect terminals TE1 and E1 of the check connector.
And maintain engine speed at 2,500 rpm.
Check the number of times the voltmeter needle
fluctuates in 10 seconds.Check the number of times the voltmeter needle fluctuates in 10 seconds.
Read and record diagnostic codes. (See page FI±25 or 27)Zero again After replacing
the oxygen sensor
Measure voltage between terminals VF 1 and E 1.
Repair the relevant diagnostic code.
CONTINUED ON PAGE FI±30Less than 8 times
Less than 8 timesReplace the ECU.
8 times of more
More than 0 V
8 times or
more
NormalZero
Zero
± EFI SYSTEMElectronic Control System (Main Oxygen Sensor)FI±129
Page 1144 of 2389
Warm up the oxygen sensor with the engine at 2,500
rpm for approx. 90 seconds. And maintain engine speed at
2,500 rpm.Disconnect the water temp. sensor connector and connect
resistor with a resistance of 4 ± 8 k
or another coded
water temp. sensor.Disconnect terminals TE1 and E1 of the check connector.
And maintain engine at 2,500 rpm.
Measure voltage between terminals VF 1 and El.Rear record diagnostic codes. (See page FI±25 or 27) CONTINUED FROM PAGE FI±129
Malfunction code(s)
(Ex. code Nos. 21, 25 and 26)
Connect terminals TE1 and E1 of the check connector. Measure voltage between terminals VF 1 and E 1 .Measure voltage between terminals VF 1 and El.Normal code, code Nos.
21, 25 and 26 Repair the relevant diagnostic code.
Disconnect the PCV hose.
Replace the oxygen sensor.Repair (Over rich)
Repair (Over lean) More than 0 V
± EFI SYSTEMElectronic Control System (Main Oxygen SensorFI±130