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