EFI SYSTEM — Electronic Control System
FI-75
VF2
In
'.o'D
J
VF1
000
Check Connector
Voltmeter
v
n
D
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0
F12409
Oxygen Sensors
I NSPECTION OF OXYGEN SENSOR
1.
WARM UP ENGINE
Allow the engine to reach 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 El. Perform the test as follows:
Warm up the oxygen sensor with the engine at 2,500 rpm
for approx. 120 seconds.
Connect terminals TE1 and El of the check connector.
And maintain engine speed at 2,500 rpm.
Replace the ECU.
i After replacing
Zero again i the oxygen
sensor
Check the number of times the voltmeter needle fluctuates in 10 seconds.
Less than 8 times
8 times
Zero
or more
Warm up the oxygen sensor with the engine at 2,500 rpm
Normal
for approx. 120 seconds. And maintain engine at
2,500 rpm.
8 times or more
Check the number of times the voltmeter needle
fluctuates in 10 seconds.
Less than 8 times
Zero
Disconnect terminals TE1 and El of the check con-
nector. And maintain engine speed at 2,500 rpm.
Measure voltage between terminals VF1 (VF2) and El
0V
More than 0 V
Read and record diagnostic codes. (See pages FI-24, 25)
Normal code, code Nos.
Malfunction code(s)
21, 25, 26 and 28
(Ex. code Nos. 21, 25, 26 and 28)
Repair the relevant diagnostic code.
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CONTINUED ON PAGE FI-76