TSRM/MK3 Supra/Repair Manual
Repair ManualWiring Diagrams
p.039
FI/EFI System40 / 126
p.041
EFI SYSTEM — Troubleshooting with Volt/Ohmmeter (7M-GE) — MK3 Supra EFI System, page 40
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FI-40 EFI SYSTEM — Troubleshooting with Volt/Ohmmeter (7M-GE) No. | Terminals | Trouble | Condition | STD Voltage 5 | THA — E2 | No voltage | Ignition switch ON | Intake air temperature 20°C (68°F) | 1—3 V [DIAGRAM: Circuit diagram showing Air Temp. Sensor (Air Flow Meter) with connections E2 and THA to ECU terminals +B (+B1) and E2, THA, E1] [DIAGRAM 1: ECU connection showing THA terminal with voltmeter connection] Text: There is no voltage between ECU terminals THA and E2. (IG SW ON) [DIAGRAM 2: ECU connection showing +B (+B1) terminal with voltmeter connection] Text: Check that there is voltage between ECU terminal +B (+B1) and body ground. (IG SW ON) OK → NO → Refer to No. 1. (See page FI-35) [DIAGRAM 3: ECU connection showing E1 terminal with ground connection] Text: Check wiring between ECU terminal E1 and body ground. OK → BAD Check air temp. sensor. (See page FI-94) → Repair or replace. BAD → OK Replace air flow meter. → Check wiring between ECU and air temp. sensor. OK → BAD Try another ECU. → Repair or replace. [DIAGRAM: Air Flow Meter with Ohmmeter connection between E2 and THA terminals] FI1272 FI1636 FI0313 FI1253