Oxygen Sensor - Toyota Supra 1990 Manual

EFI SYSTEM - Electronic Control System
FI-119
Oxygen Sensor
INSPECTION 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 terminals
VFl 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. 90 seconds.
Using SST, connect terminals TE1 and E1 of the check
Replace the ECU
connector. SST 09843·18020
And maintain engine speed at 2,500 rpm.
Zero again
After replaceing
the oxygen sensor
Check the number of times the voltmeter needle fluctuates in 10 seconds.
I
Less than 8 times
8 times
Zero
or more
Warm up the Oxygen sensor with the engine at 2,500
Normal
rpm for approx. 90 seconds. And maintain engine at
2,500 rpm.
8 times or more
Check that the number of times the voltmeter needle
fluctuates in 10 seconds.
Zero
Less than 8 times
Disconnect terminals TE1 and E1 of the check connector.
And maintain engine speed at 2,500 rpm.
Measure voltage between terminals VF1 and E1.
!OV
More than 0 V
I
Read and record diagnostic codes.
I
Normal code, code 21,
Malfunction code(5)
code 25 and code 26
(ex. code 21, code 25 and code 26)
Repair the relevent diagnostic code.
I
2
3
4
CONTINUED ON PAGE FI·120