METER / GAUGE / DISPLAY: METER / GAUGE SYSTEM (for HV Model): TERMINALS OF ECU; 2021 MY Corolla Corolla HV [04/2020

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)

Wiring Color

Terminal Description

Signal Input/output

Condition

Specified Condition

I4-1 (B) - Body ground

SB - Body ground

Auxiliary battery

Power switch off

11 to 14 V

I4-9 (CANH)

CAN communication line

Input/output

I4-10 (MSCL)*1

Local bus communication line

Input/output

I4-11 (SW3) - Body ground

BR - Body ground

Light control rheostat (Ground)

Always

Below 1 Ω

I4-14 (FV) - Body ground

GR - Body ground

Fuel sender gauge (Power source)

Input

Power switch on (IG)

Pulse generation

(See waveform 2)

I4-15 (MSTI) - Body ground

V - Body ground

Steering pad switch signal

Input

Power switch on (IG), up, down, right and left switches on steering pad switch not pushed

4.8 to 5.2 V

I4-16 (SW2) - Body ground

P - Body ground

Light control rheostat signal

Input

Power switch on (IG), light control rheostat knob fully turned downward → fully turned upward

Below 1 V → 4 to 6 V

(Gradually change)

I4-17 (TC) - Body ground

V - Body ground

Tail cancel switch signal

Input

Power switch on (IG), 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

I4-19 (EP) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

I4-20 (SI) - Body ground

GR - Body ground

Speed signal for other system (Input)

Input

Power switch on (IG), wheel being rotated

Pulse generation

(See waveform 1)

I4-22 (B) - Body ground

G - Body ground

Auxiliary battery

Always

11 to 14 V

I4-23 (ES) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

I4-24 (FE&B) -Body ground

P - Body ground

Fuel sender gauge (Ground)

Always

Below 1 Ω

I4-25 (CANL)

CAN communication line

Input/output

I4-27 (MSCH)*1

Local bus communication line

Input/output

I4-31 (FR) - I4-24 (FE&B)

R - P

Fuel level signal

Input

Power switch on (IG), fuel level full → low (fuel level warning light on)

Pulse generation

(See waveform 2)

I4-32 (MSM+) - Body ground

GR - Body ground

Steering pad switch signal

Input

Power switch on (IG), OK and back switches on steering pad switch not pushed

4.8 to 5.2 V

I4-34 (SW1) - Body ground

R - Body ground

Light control rheostat (Power source)

Input

Power switch on (IG)

4 to 6 V

I4-35 (ILL-) - Body ground

L - Body ground

Illumination signal

Output

Taillights off → on

Below 1 V → Pulse generation

I4-36 (+S) - Body ground

SB - Body ground

Speed signal for other systems (Output)

Output

Power switch on (IG), wheel being rotated

Pulse generation

(See waveform 1)

I4-38 (IG+) - Body ground

LG - Body ground

Power switch signal

Input

Power switch off → Power switch on (IG)

Below 1 V → 11 to 14 V

I5-1 (LL) - Body ground

R - Body ground

LH turn signal

Output

LH turn indicator light off → blinking

Below 1 V → 11 to 14 V ←→ Below 1 V

I5-2 (LR) - Body ground

V - Body ground

RH turn signal

Output

RH turn indicator light off → blinking

Below 1 V → 11 to 14 V ←→ Below 1 V

I5-5 (TRNL) - Body ground

V - Body ground

LH turn signal

Output

LH turn indicator light off → blinking

Below 1 V → 11 to 14 V ←→ Below 1 V

I5-6 (TRNR) - Body ground

G - Body ground

RH turn signal

Output

RH turn indicator light off → blinking

Below 1 V → 11 to 14 V ←→ Below 1 V

I5-7 (LP) - Body ground

P - Body ground

Security indicator signal

Input

Security indicator light off → blinking

Below 2 V → Pulse generation

I5-14 (WLVL) - Body ground*2

L - Body ground

Washer fluid level signal

Input

Power switch on (IG), washer fluid level not low → low

11 to 14 V → Below 1 V

I5-17 (HAZ) - Body ground

P - Body ground

Hazard warning signal switch signal

Input

Hazard warning signal switch off → on

11 to 14 V → Below 1 V

I5-19 (RCSB) - Body ground

W - Body ground

Rear center seat belt warning signal

Input

Power switch on (IG) rear center seat belt unfastened → fastened

Below 1 V → 11 to 14 V

I5-23 (S) - Body ground

G - Body ground

Engine oil pressure signal

Input

Engine started → not started

11 to 14 V → Below 1 V

I5-24 (INT) - Body ground*4

B - Body ground

Tire pressure warning system signal

Output

Power switch on (IG), OK switch on steering pad switch not pushed

8 to 15 V

I5-31 (OILW) - Body ground

B - Body ground

Engine oil level signal

Input

Power switch on (IG), engine oil level not low → low

Below 1 V → 11 to 14 V

I5-33 (LST1) - Body ground*3

Y - Body ground

Fuel lid status signal

Input

Power switch off

11 to 14 V

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

Please Wait Fuel Door Opening

Pulse generation

(See waveform 4)

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

Ready to Refuel

Pulse generation

(See waveform 5)

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

Close Fuel Lid

Pulse generation

(See waveform 6)

I5-35 (RRSB) - Body ground

R - Body ground

Rear right seat belt warning signal

Input

Power switch on (IG) rear right seat belt unfastened → fastened

Below 1 V → 11 to 14 V

I5-36 (RLSB) - Body ground

G - Body ground

Rear left seat belt warning signal

Input

Power switch on (IG) rear left seat belt unfastened → fastened

Below 1 V → 11 to 14 V

*1: w/ Audio Tab Display
*2: w/ Washer Fluid Level Warning
*3: w/ Canister Pump Module
*4: w/ Tire Pressure Warning System

Waveform 1:

Item	Condition
Tester connection	I4-14 (FV) - Body ground
Tool setting	2.5 V/DIV., 20 ms./DIV.
Condition	Power switch on (IG)
Specified Condition	4.5 to 5.5 V

Waveform 2:

Item	Condition
Tester connection	I4-20 (SI) - Body ground I4-36 (+S) - Body ground
Tool setting	5 V/DIV., 20 ms./DIV.
Condition	Power switch on (IG), 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 3:

Item	Condition
Tester connection	I4-31 (FR) - I4-24 (FE&B)
Tool setting	2.5 V/DIV., 20 ms./DIV.
Condition	Power switch on (IG), fuel level full → low (fuel level warning light on)

HINT:

(A) varies depending on the fuel level.

Fuel level full: 4.2 to 4.6 V
Fuel level low (fuel level warning light on): 0.3 to 1.1 V

Waveform 4:

Item	Condition
Tester Connection	I5-33 (LST1) - Body ground
Tool setting	5 V/DIV., 20 ms./DIV.
Condition	The following message (interrupt display) being displayed on the multi-information display: Please Wait Fuel Door Opening

HINT:

This waveform is output when the internal pressure of the fuel tank is higher than the ambient pressure when the fuel lid opener switch is operated.

Waveform 5:

Item	Condition
Tester Connection	I5-33 (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 6:

Item	Condition
Tester Connection	I5-33 (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.