METER / GAUGE / DISPLAY: METER / GAUGE SYSTEM (except 12.3 Inch Display): TERMINALS OF ECU; 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [11/2022

TERMINALS OF ECU

COMBINATION METER ASSEMBLY

(a) Measure the voltage and resistance and check for pulses according to the value(s) in the table below.

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

Power source for auxiliary battery

Ignition switch off*1
Always*2

11 to 14 V

I4-6 (IG+) - Body ground

Power source for IG relay

IG OFF → IG ON

Below 1 V → 11 to 14 V*1
Below 1 V → 10.5 to 16 V*2

I4-8 (+S) - Body ground

Vehicle speed output signal

Ignition switch ON, wheel being rotated

Pulse generation

(See waveform 1)

I4-9 (S) - Body ground*1

Engine oil pressure signal

Engine started → not started

11 to 14 V → Below 1 V

I4-11 (SW) - Body ground*2

Brake fluid level warning switch signal

Ignition switch ON, brake fluid level not low (brake warning light/red (malfunction) off) → low (brake warning light/red (malfunction) on)

11 to 14 V → Below 1 V

I4-12 (HZSW) - Body ground

Hazard warning signal switch signal

Hazard warning signal switch off → on

11 to 14 V → Below 1 V

I4-13 (WLVL) - Body ground*3

Washer fluid level signal

Ignition switch ON, washer fluid level not low → low

11 to 14 V → Below 1 V

I4-14 (OILW) - Body ground

Engine oil level sensor signal

Ignition switch ON, engine oil level not low → low

Below 1 V → 11 to 14 V

I4-23 (ILL-) - Body ground

Illumination signal

Taillights off → on

Below 1 V → Pulse generation

I4-25 (SI) - Body ground

Vehicle speed input signal

Ignition switch ON, wheel being rotated

Pulse generation

(See waveform 1)

I4-27 (VCM) - Body ground*2

Vacuum warning switch signal

Engine started, vacuum warning switch off (brake warning light/red (malfunction) off) → on (brake warning light/red (malfunction) on)

11 to 14 V → Below 1 V

I4-28 (LST1) - Body ground*1

Fuel lid status signal

Ignition switch OFF

11 to 14 V

The following message (interrupt display) being displayed on the multi-information display:

"Ready to Refuel"

Pulse generation

(See waveform 4)

The following message (interrupt display) being displayed on the multi-information display:

"Close Fuel Lid"

Pulse generation

(See waveform 5)

I5-2 (B) - Body ground

Power source for auxiliary battery

Ignition switch off*1
Always*2

11 to 14 V

I5-5 (LL) - Body ground

Front/side turn signal flasher signal

(LH side)

Turn indicator light (LH) blinking

11 to 14 V ←→ Below 1 V

Turn indicator light (LH) off

Below 1 V

I5-6 (LR) - Body ground

Front/side turn signal flasher signal

(RH side)

Turn indicator light (RH) blinking

11 to 14 V ←→ Below 1 V

Turn indicator light (RH) off

Below 1 V

I5-7 (FR) - I5-25 (FE&B)

Fuel level signal

Ignition switch ON, fuel receiver gauge indicates F → E (fuel level warning light on)

Pulse generation

(See waveform 2)

I5-10 (TC) - Body ground

Tail cancel switch signal

Ignition switch ON, light control rheostat knob not fully turned upward (Tail cancel switch off) → fully turned upward (Tail cancel switch on)

Below 1 V → 4 to 6 V

I5-11 (SW1) - Body ground

Light control rheostat (Power source)

Ignition switch ON

4 to 6 V

I5-12 (MSTI) - Body ground

Steering pad switch without touch detection function signal

Ignition switch ON, up, down, left and right switches on steering pad switch not pushed

4.8 to 5.2 V

I5-14 (CANL)

CAN communication signal

I5-15 (TX-)

Local bus communication signal

I5-21 (TRNR) - Body ground

Rear turn signal flasher signal

(RH side)

Turn indicator light (RH) blinking

11 to 14 V ←→ Below 1 V

Turn indicator light (RH) off

Below 1 V

I5-22 (TRNL) - Body ground

Rear turn signal flasher signal

(LH side)

Turn indicator light (LH) blinking

11 to 14 V ←→ Below 1 V

Turn indicator light (LH) off

Below 1 V

I5-23 (FV) - Body ground

Power source for fuel sender gauge

Ignition switch ON

Pulse generation

(See waveform 3)

I5-25 (FE&B) - Body ground

Ground for fuel sender gauge

Always

Below 1 Ω

I5-26 (SW3) - Body ground

Ground for trip switch

Always

Below 1 Ω

I5-28 (SW2) - Body ground

Light control rheostat signal

Ignition switch ON, light control rheostat knob fully turned downward → fully turned upward

Below 1 V → 4 to 6 V

(Gradually change)

I5-29 (MSM+) - Body ground

Steering pad switch without touch detection function signal

Ignition switch ON, OK and back switches on steering pad switch not pushed

4.8 to 5.2 V

I5-31 (CANH)

CAN communication signal

I5-32 (TX+)

Local bus communication signal

*1: for HV Model
*2: for Gasoline Model
*3: w/ Washer Fluid Level Warning

Waveform 1:

Item	Condition
Tester connection	I4-8 (+S) - Body ground I4-25 (SI) - Body ground
Tool setting	5 V/DIV., 20 ms./DIV.
Condition	Ignition switch ON, wheel being rotated

HINT:

When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

Waveform 2:

Item	Condition
Tester connection	I5-7 (FR) - I5-25 (FE&B)
Tool setting	2.5 V/DIV., 20 ms./DIV.
Condition	Ignition switch ON, fuel receiver gauge indicates F → E (fuel level warning light on)

HINT:

(A) varies depending on the fuel level.

Fuel level full: 4.0 to 4.6 V
Fuel level low (fuel level warning light on): 0.3 to 0.9 V

Waveform 3:

Item	Condition
Tester connection	I5-23 (FV) - Body ground
Tool setting	2.5 V/DIV., 20 ms./DIV.
Condition	Ignition switch ON
Specified Condition	4.5 to 5.5 V

Waveform 4:

Item	Condition
Tester connection	I4-28 (LST1) - Body ground
Tool setting	5 V/DIV., 20 ms./DIV.
Condition	The following message (interrupt display) being displayed on the multi-information display: "Ready to Refuel"

Waveform 5:

Item	Condition
Tester connection	I4-28 (LST1) - Body ground
Tool setting	5 V/DIV., 20 ms./DIV.
Condition	The following message (interrupt display) being displayed on the multi-information display: "Close Fuel Lid"

HINT:

This waveform is output when the fuel lid opener switch is operated if the fuel lid is open and any of the following conditions are met:

The vehicle has been driven for 1 km (0.6 mile) or more at a speed of 50 km/h (31 mph) or more.
30 minutes or more have elapsed since the fuel lid opener switch was operated.