Troubleshooting Flowchart - ECU
6-21flowchartECU self-diagnosis (code 0) flowchart. Wire colors referenced: YEL, GRN/ORN, BLK; ground point G101; ECU terminals B6, A2, A4; circuit fuse No. 1.
Troubleshooting Flowchart - ECU
1
Check Engine warning light isn't on for two seconds after ignition is first turned on.
2
Is oil pressure warning light on?
NO
Inspect No. 1 fuse.
Inspect No. 1 fuse.
Is No. 1 fuse OK?
YES
3
Turn the ignition switch OFF.
4
Connect the PGM-FI test harness between the ECU and connector (page 6-19).
5
Connect B6 terminal to body ground.
6
Turn the ignition switch ON.
7
Is Check Engine warning light on?
NO
- Replace warning light bulb. - Repair open in GRN/ORN wire between ECU (B6) and combination meter.
YES
8
Connect the following terminals individually to B6: A2, A4
9
Is Check Engine warning light on?
NO
- Repair open in BLK wire between ECU (A2) and G101. - Repair open in BLK wire between ECU (A4) and G101.
YES
Substitute a known-good ECU and recheck. If symptom/indication goes away, replace the original ECU.
(cont'd)