| Last Modified: 08-22-2025 | 6.11:8.1.0 | Doc ID: RM0000003TPDE3G |
| Model Year Start: 2026 | Model: GR Corolla | Prod Date Range: [08/2025 - ] |
| Title: SEAT BELT: SEAT BELT WARNING SYSTEM (w/o Occupant Classification System): TERMINALS OF ECU; 2026 MY Corolla Corolla Hatchback Corolla HV GR Corolla [08/2025 - ] | ||
TERMINALS OF ECU
CHECK POWER DISTRIBUTION BOX ASSEMBLY AND MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)
(a) Remove the main body ECU (multiplex network body ECU) from the power distribution box assembly.
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![2025 - 2026 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2024 - ]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL](/t3Portal/stylegraphics/info.gif)
(b) Reconnect the power distribution box assembly connectors.
(c) Measure the voltage and resistance according to the value(s) in the table below.
|
Terminal No. (Symbol) |
Terminal Description |
Condition |
Specified Condition |
|---|---|---|---|
|
MB-13 (GND1) - Body ground |
Ground |
Always |
Below 1 Ω |
|
MB-14 (GND2) - Body ground |
Ground |
Always |
Below 1 Ω |
|
MB-26 (BECU) - Body ground |
Auxiliary battery power supply |
Always |
11 to 14 V |
|
MB-27 (IGR) - Body ground |
Ignition power supply |
Ignition switch off |
Below 1 V |
|
Ignition switch ON |
11 to 14 V |
(d) Install the main body ECU (multiplex network body ECU).
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(e) Measure the voltage and check for pulses according to the value(s) in the table below.
|
Terminal No. (Symbol) |
Terminal Description |
Condition |
Specified Condition |
|---|---|---|---|
|
8H-18 (LCTY) - Body ground |
Rear door courtesy light switch (for LH) input |
Rear door LH open → closed |
Below 1 V → 11 to 14 V or pulse output (maximum 14 V)* |
|
8H-8 - Body ground |
Front passenger seat belt buckle switch signal |
Front passenger seat belt fastened |
11 to 14 V |
|
Front passenger seat belt unfastened |
Below 1 V |
||
|
8H-9 - Body ground |
Front passenger seat occupant detection sensor signal |
Ignition switch ON, front passenger seat occupied |
Below 1 V |
|
Ignition switch ON, front passenger seat not occupied |
11 to 14 V |
||
|
8H-10 - Body ground |
Rear RH seat belt buckle switch signal |
Rear RH seat belt fastened |
11 to 14 V |
|
Rear RH seat belt unfastened |
Below 1 V |
||
|
8H-25 - Body ground |
Rear LH seat belt buckle switch signal |
Rear LH seat belt fastened |
11 to 14 V |
|
Rear LH seat belt unfastened |
Below 1 V |
||
|
8H-26 - Body ground |
Rear center seat belt buckle switch signal |
Rear center seat belt fastened |
11 to 14 V |
|
Rear center seat belt unfastened |
Below 1 V |
||
|
8H-27 (RCTY) - Body ground |
Rear door courtesy light switch (for RH) input |
Rear door RH open → closed |
Below 1 V → 11 to 14 V or pulse output (maximum 14 V)* |
- *: Differs depending on the vehicle model
CHECK COMBINATION METER ASSEMBLY
(a) Disconnect the I4 combination meter assembly connector.
(b) Measure the resistance and voltage according to the value(s) in the table below.
HINT:
Measure the values on the wire harness side with the connector disconnected.
|
Terminal No. (Symbol) |
Terminal Description |
Condition |
Specified Condition |
|---|---|---|---|
|
I4-1 (EP) - Body ground |
Ground |
Always |
Below 1 Ω |
|
I4-2 (ES) - Body ground |
Ground |
Always |
Below 1 Ω |
|
I4-5 (B) - Body ground |
Auxiliary battery power supply |
Always |
11 to 14 V |
|
I4-6 (IG+) - Body ground |
Ignition power supply |
Ignition switch off |
Below 1 V |
|
Ignition switch ON |
11 to 14 V |
||
|
I4-29 (BKL) - Body ground |
Driver side seat belt buckle switch signal |
Driver side seat belt fastened |
1 MΩ or higher |
|
Driver side seat belt unfastened |
Below 1 Ω |
|
|