FI/EFI System, page 39

EFI SYSTEM — Troubleshooting for EFI Electronic Circuit with Volt/Ohmmeter

No. | Terminals | Trouble | Condition | STD Voltage
4 | THW — E₂ | No voltage | Ignition switch ON | Coolant temperature 80°C (176°F) | 0.1 — 0.5 V

[Circuit diagram showing Water Temp. Sensor connected to ECU with terminals +B, THW, E₂, E₁, and ground]

FI4031

Voltmeter | ECU
THW | E₂

① There is no voltage between ECU terminals THW and E₂. (IG S/W ON)

② Check that there is voltage between ECU terminal +B and body ground. (IG S/W ON)

OK | NO

③ Check water temp. sensor. | Refer to No. 1.

BAD | OK

Replace water temp. sensor. | Check wiring between ECU and water temp. sensor.

OK | BAD

Try another ECU. | Repair or replace wiring.

[Diagram 2 showing voltmeter connection]
FI4034

[Diagram 3 showing ohmmeter connection]
FI4036