USA MR2 AW11 NA
ECU Pin Identification
Provided by Richard White
4A-G Electronic Controlled Unit (ECU), 85~86’ AW11 MR2 US Market, Connector Shown.
Note: Toyota P/N 85’ (M/T) 89661-17020-84; 86’ (auto) 89661-17050-84; 87’ (M/T), 89661-17021; 87’ (auto) 89661-17051, 88~89’ 89661-17201
V Connector
| Pin No. | Symbol | Color | Terminal |
| 1 | NSW | B-W | Neutral Start Switch (86 MR2 A/T) |
| 2 | VF | R-W | Check connector |
| 3 | STA | B | Starter switch |
| 4 | No. 10 | L | No. 3, 4 injector |
| 5 | E01 | BR | Engine ground (Power) |
| 6 | S/TH | G-O | Vacuum switching valve (VSV) |
| 7 | E1 | BR | Engine ground |
| 8 | IGT | B-W | Igniter |
| 9 | No. 20 | Y | No. 1, 2 injector |
| 10 | E02 | BR | Engine ground (Power) |
U Connector
| Pin No. | Symbol | Color | Terminal |
| 1 | NE | W | Engine revolution sensor |
| 2 | |||
| 3 | G+ | B | Engine revolution sensor |
| 4 | G- | W | Engine revolution sensor |
| 5 | IGF | B-Y | Igniter |
| 6 | IDL | B | Throttle sensor |
| 7 | T | W | Check connector |
| 8 | W | G-W | Warning light (WAN) |
| 9 | FPU | G-B | VSV (FPU) |
| 10 | THW | W | Water temp. sensor |
| 11 | VTA | R | Throttle sensor |
| 12 | VCC | Y | Throttle sensor |
| 13 | OX | B | Oxygen sensor |
| 14 | E2 | BR | Sensor Earth |
| 15 | A/C | B-W | A/C Magnet clutch |
| 16 | TSW | G-Y | Water Temp Switch |
| 17 | |||
| 18 | VISC | B | Vacuum switching valve [Idle up](I-UP) |
T Connector
| Pin No. | Symbol | Color | Terminal |
| 1 | +B1 | B | Main relay |
| 2 | BaTT | W-R | Battery |
| 3 | THA | Y | Inlet air temp. sensor |
| 4 | VS | Y-L | Air flow meter |
| 5 | VC | L-R | Air flow meter |
| 6 | L1 | Y-L | (86’ MR2 A/T), ECT Computer |
| 7 | L3 | Y-R | (86’ MR2 A/T), ECT Computer |
| 8 | +B | B-R | Main relay |
| 9 | |||
| 10 | SPD | V-W | Speedometer |
| 11 | |||
| 12 | E21 | B-R | Sensor earth |
| 13 | L2 | Y-G | (86’ MR2 A/T), ECT Computer |
| 14 | ECT | P-W | (86’ MR2 A/T), ECT Computer (OD1) |
Source: Toyota Repair Manuals for MR2, 1985 and 1986