SELF-DIAGNOSIS FUNCTION
F-86flowchartCODE NO.15 OXYGEN SENSOR
1
Are there any poor connections in oxygen sensor circuit?
Yes
Repair or replace connector
No
2
Is oxygen sensor output voltage OK? (Refer to page F-138)
No
Replace oxygen sensor (Refer to page F-138)
Yes
3
Is there continuity between oxygen sensor and ECU terminal 2N?
No
Check for open circuit in wiring from oxygen sensor to ECU
Yes
4
Is ECU terminal 2N voltage OK?
No
Check for short circuit in wiring from oxygen sensor to ECU
Yes
5
Is sensitivity of oxygen sensor OK? (Refer to page F-138)
No
same as step 2
Yes
6
Replace ECU (Refer to page F-127)
NOTE
If Code Nos.15 and 17 are both present, first perform the checking procedure for Code No.17
CODE NO.17 FEEDBACK SYSTEM
1
Warm up engine and run it at 2,500–3,000 rpm for 3 min.
2
Does monitor lamp of Self-Diagnosis Checker illuminate at idle?
No
Check for air leak in vacuum hoses or emission components; Check for contaminated oxygen sensor; Check for insufficient fuel injection
Yes
3
Are spark plugs clean?
No
Clean or replace spark plugs
Yes
4
Is oxygen sensor voltage OK? (Refer to page F-138)
No
Replace oxygen sensor (Refer to page F-138)
Yes
5
Is same Code No. present after performing after-repair procedure? (Refer to page F-88)
No
Check for short circuit in wiring from oxygen sensor to ECU terminal 2N
Yes
6
Is there continuity between oxygen sensor and ECU terminal 2N?
No
Check for open circuit in wiring from oxygen sensor to ECU terminal 2N
Yes
7
Is ECU terminal 2N voltage OK? (Refer to page F-127)
No
Check for short circuit in wiring from oxygen sensor to ECU
Yes
8
Replace ECU (Refer to page F-127)
Circuit Diagram
CODE NO.15/17 OXYGEN SENSOR Circuit Diagram
Oxygen sensorECU:2NBlack (F)
Oxygen sensorgroundBlack with Light Green stripe (F)