Lexus NX: Terminals Of Ecu
TERMINALS OF ECU
CHECK COMBINATION METER ASSEMBLY
(a) Disconnect the I10 combination meter assembly connector.
(b) Measure the resistance and voltage according to the value(s) in the table below.
| Tester Connection | Wiring Color | Terminal Description | Condition | Specified Condition |
|---|---|---|---|---|
| I10-21 (IG+) - Body ground | B - Body ground | IG power supply | Power switch on (IG) → off | 11 to 14 V → Below 1 V |
| I10-22 (B) - Body ground | Y - Body ground | Battery power supply | Always | 11 to 14 V |
| I10-31 (ES) - Body ground | W-B - Body ground | Ground | Always | Below 1 Ω |
(c) Reconnect the I10 combination meter assembly connector.
(d) Measure the voltage according to the value(s) in the table below.
| Tester Connection | Wiring Color | Terminal Description | Condition | Specified Condition |
|---|---|---|---|---|
| I10-6 (P/SB) - Body ground | L - Body ground | Front passenger seat belt buckle switch signal | Power switch on (IG), front passenger seat occupied, seat belt unfastened → fastened | 11 to 14 V → Below 1 V |
| I10-12 (RRSB) - Body ground | W - Body ground | Rear RH seat belt buckle switch signal | Rear RH seat belt unfastened → fastened | 11 to 14 V → Below 1 V |
| I10-13 (RCSB) - Body ground | B - Body ground | Rear center seat belt buckle switch signal | Rear center seat belt unfastened → fastened | 11 to 14 V → Below 1 V |
| I10-14 (RLSB) - Body ground | G - Body ground | Rear LH seat belt buckle switch signal | Rear LH seat belt unfastened → fastened | 11 to 14 V → Below 1 V |
| I10-35 (RLMT) - Body ground | W - Body ground | Rear LH seat belt warning light signal | Rear LH seat belt unfastened → fastened | 11 to 14 V → Below 1 V |
| I10-36 (RCMT) - Body ground | G - Body ground | Rear center seat belt fastened | Rear center seat belt unfastened → fastened | 11 to 14 V → Below 1 V |
| I10-37 (RRMT) - Body ground | L - Body ground | Rear RH seat belt warning light signal | Rear RH seat belt unfastened → fastened | 11 to 14 V → Below 1 V |
CHECK AIRBAG ECU ASSEMBLY
| Terminal No. | Terminal Symbol | Destination |
|---|---|---|
| Q23-15 | LBE+ | Front seat inner belt assembly LH |
| Q23-23 | LBE- | Front seat inner belt assembly LH |
| P23-9 | FSR+ | Occupant detection ECU |
| P23-17 | FSR- | Occupant detection ECU |
CHECK OCCUPANT DETECTION ECU
HINT:
Since the occupant detection ECU uses waterproof connectors, the voltage and waveform cannot be inspected directly. Standard voltage readings and waveforms are indicated for reference only.
| Terminal No. (Symbol) | Wiring Color | Terminal Description | Condition | Specified Condition |
|---|---|---|---|---|
| f14-1 (SVC1) - f14-5 (SGD1) | R - G | Front occupant classification sensor LH power supply | Power switch on (IG) | 4.9 to 5.1 V |
| f14-2 (SVC3) - f14-6 (SGD3) | GR - W | Rear occupant classification sensor LH power supply | Power switch on (IG) | 4.9 to 5.1 V |
| f14-3 (SIG1) - f14-5 (SGD1) | P - G | Front occupant classification sensor LH signal | Power switch on (IG) | Pulse generation |
| f14-4 (SIG3) - f14-6 (SGD3) | SB - W | Rear occupant classification sensor LH signal | Power switch on (IG) | Pulse generation |
| f14-5 (SGD1) - f15-3 (GND) | G - W-B | Front occupant classification sensor LH ground | Always | Below 1 V |
| f14-6 (SGD3) - f15-3 (GND) | W - W-B | Rear occupant classification sensor LH ground | Always | Below 1 V |
| f15-1 (+B) - f15-3 (GND) | W - W-B | Power source (+B) | Power switch off | 11 to 14 V |
| f15-2 (DIA) | GR | Diagnosis (DLC3) | -* | -* |
| f15-3 (GND) - Body ground | W-B - Body ground | Ground | Always | Below 1 V |
| f15-4 (FSR-) - f15-3 (GND) | LG - W-B | Airbag ECU assembly communication signal | Always | Below 1 V |
| f15-5 (BGND) - f15-3 (GND) | P - W-B | Front Passenger side buckle switch ground | Always | Below 1 V |
| f15-6 (IG2) - f15-3 (GND) | B - W-B | Power source (IG) | Power switch on (IG) | 11 to 14 V |
| f15-7 (FSR+) - f15-4 (FSR-) | L - LG | Airbag ECU assembly communication signal | Power switch on (IG) | Pulse generation |
| f15-8 (BSW) - f15-5 (BGND) | G - P | Front Passenger side buckle switch signal | Always | Pulse generation |
- *: As this is a line that is connected to other systems, voltage changes according to the systems that are connected.
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